Image of home3_b.gif

Image of wlan logo #1.gif

KA3SDP (USA) installs Alford Slot antenna

Antennas, Amplifiers and Propagation Topics 

(for Microwave WLANs)

LAST UPDATED:   Wednesday 23rd September 2015

    Click on the headings below

Site Upkeep Links




Standard Wi-Fi or WLAN equipment can be improved by adding "high gain" antenna.

The gain of the antenna at each end of a link multiply together and this table attempts to conservatively indicate how far you can expect to get a FULL SPEED CONNECTION by increasing the "gain" of the antenna used at each end of the link.

Henry O'Tani (G8OTA)

Fof full data to 85km / 53 Miles click on the above table or follow this link: Table 1.htm

Sept 2015



  NOTES on 802.11 rain attenuation

propagation thru rain.htm

from John Waters


PolarPlot is a program that lets you see what the polar diagram of your rotatable beam antenna

actually looks like where it is operating.  It has been written for the ham radio community interested

in knowing more about their beam antennas. 

You can download and try out PolarPlot to see if you like the look of it. The program will operate fully for 30 runs during a 15 day period. You can check that it works on your equipment and take take a look at some sample antenna plots.  All that is needed (apart from your rig of course!) to measure your own or someone else's antenna is a standard PC with a sound card.  For more information look at this copy of the user guide  PolarPlot runs on Windows 95/98, Windows/NT4 and Windows 2000, desktop machines and even laptops!

With PolarPlot you can measure the polar diagram of the antenna and check for abnormalities - compare plots taken before and after changes to the design or location - check the -3dB beamwidth - look at the front to back ratio - see the size and position of the sidelobes - compare the design pattern to the actual - gain a better understanding of the antenna. You can view the plot on a circular or rectangular grid, with either log or linear scales. The screenshot on the right is a 2m beam before and after a re-build - the blue is the before, and the red is the after!. Take a look at some more screenshots of PolarPlot in action.PolarPlot 2m 8el after rebuild.jpg (74658 bytes)

Image of 5.jpg

Image of 6.jpg

  G4JNT Microwave Broadband (ATV) path prediction program for PCs

A set of Public Domain programs for plotting microwave (broadband amateur television) line of sight radio pathways,using NGR/Locator Grid. Draws Localmaps around a given point. Point-to-point Terrain paths and optical horizon Views.

Mainland Britain only. MicroSoft DOS or Windows.


Image of 7.jpg


  VE2DBE "RADIO MOBILE" path prediction program for PCs

Radio Mobile Version 3.5.4 Radio Propagation and Virtual Mapping Freeware by VE2DBE.

An up-to-date Windows program useable world-wide requiring additional mapping and topographical data obtainable from other external sources.....

Elevation data For most of the world is available

The software also provides 3D views, stereoscopic views, and animation.

Freeware by VE2DBE


Getting started in

"Radio Mobile"

G8GTZ (20/3/2002)

  Getting started in "Radio Mobile"

Radio Mobile is a fantastic program for predicting links and radio coverage. However, it does take some time to get to know and the user documentation is not the best! So here is the G8GTZ how to get started guide.

Download in original Word format

Noel - G8GTZ


ONLINE Terrain Plot

(United Kingdom Only)

  Online Terrain Plot U.K.

This page is an online implementation of a program used by UK radio amateurs since 1993. Credit is due for the original Power Basic design, logic and implementation Andy Talbot G4JNT



Multiple packet capture sources
Runtime network sorting by AP MAC address (bssid)
IP block detection via ARP and DHCP packet dissection
Cisco product detection via CDP
Ethereal and tcpdump compatable file logging
Airsnort-compatable "interesting" (cryptographically weak) logging
Secure SUID behavior
Cloaked network detection
Grouping and custom naming of SSIDs
Multiple clients viewing a single capture stream
Graphical mapping of data
Cross-platform support (handheld linux and BSD)

  Kismet 802.11b Wireless Network Sniffer (Linux Based)

What is it?

Kismet is a 802.11b wireless network sniffer. It is capable of sniffing using almost any wireless card supported in Linux, including Prism2 based cards supported by the Wlan-NG project (Linksys, Dlink, Rangelan, etc), cards which support standard packet capture via libpcap (Cisco), and limited support for cards without RF Monitor support.

Author: Mike Kershaw (



  Net Stumbler is a website dedicated to wireless networking technology and security of all kinds. We do our best to keep our website up to date with the latest wireless news - we really appreciate user submitted stories. is also the official home of the NetStumbler software.

NetStumbler is a Windows utility for 802.11b based wireless network auditing written by Marius Milner.

March 2004


  SMART ID - WFS-1 WI-FI Detector

It is becoming increasingly difficult not to be caught up in WiFi traffic since so many homes and businesses are taking advantage of this technology. Unfortunately, the ever-decreasing prices and ever-improving ease-of-use has also caused wireless networks to be real security problems within businesses and institutions. At a personal level, it would be useful to have a way to know where these public "hotspots" are without having to carry around equipment that makes you look like an extra from a Star Trek set. At a corporate level, it would be extremely advantageous to have a means to detect rogue WiFi equipment at all company sites without having to spend many thousands of dollars on an enterprise-level WLAN detection system.

A solution may be at hand with the appearance of two "pocket-sized" 802.11 detectors on the market: the Smart ID WFS-1 and the Kensington WiFi Finder. Both devices claim to detect 802.11b and 802.11b/g traffic and report the strength of the signals. They each cost in the area of $30 USD. The question is: how well do they work and how can you use them for both personal information gathering and corporate protection?

Bob Rudis
September 2, 2003

March 2004


  Understanding Antenna Radiation Patterns

Understanding and Using Antenna Radiation Patterns
By Joseph H. Reisert

Each antenna supplier/user has different standards as well as plotting formats.  Each format has its own pluses and minuses.  Hopefully this technical note will shed some light on understanding and using antenna radiation patterns.

All antennas have directional qualities.  They do not radiate power equally in all directions.  Therefore, antenna radiation patterns or plots are a very important tool to both the antenna designer and the end user.  These plots show a quick picture of the overall antenna response.
However, radiation patterns can be confusing.

March 2004


Image of home3_b.gif

  Click on the headings below


Image of 17.jpg

  Aironet Wireless Communications

11 Mbps Wireless LAN Solution For Small Businesses About Wireless/ Evolution of Wireless Advantages Glossary Future of WLAN What is Wireless Local Area Networking?  In the simplest of terms, WLAN is local area networking without wires, providing all the features and benefits of traditional LAN  technologies like... 


October 2, 2010


DIY 2.4GHz Yagi Antenna


Easy to Build WIFI 2.4GHz Yagi Antenna

"This antenna will extend the range of your WiFi or 2.4GHz devices (like surveillance cameras) into many miles and kilometers. A yagi antenna is basically a telescope for radio waves. I tired the pringle can antenna and the Yagi beats it hands down in performance."

Dec 2014



  CanTenna - WB8ERJ

I have come up with my own version of the classic "cantenna" using 4 inch diameter aluminum dryer vent pipe, and a 4 to 6 inch pipe adapter. Although the basic design is the same as other cantenna type antennas, the materials I ended up using are a bit different. Preliminary results show a gain of 15 DBi. Not bad for less than $10 worth of materials!

Mike Thompson WB8ERJ

Check out Mike's Web pages:
 My Ham Radio page:

March 2004




We have been experimenting with waveguide antenna, made from old food cans, to massively extend the range of 802.11b wireless networks. All that was required was fitting, in the correct place, a driven element consisting of a short piece of copper wire soldered into the centre of an N-type connector.

One of the antennas made from a J&B whiskey tin.

This was evolved primarily since the Pringle's can antenna. The Pringle's can, being cardboard, does not last long in a storm, and it is very hard to affix connectors securely. The dipole-less "yagi" bit inside is fiddly to make, and initial tests show the waveguide cans to work better.


Dec 2004


Cisco Aironet





Every wireless Local Area Network (LAN) deployment is different. When engineering an in-building solution, varying facility sizes, construction materials, and interior divisions raise a host of transmission and multipath considerations. When implementing a building-to-building solution, distance, physical obstructions between facilities, and a number of transmission points involved must be accounted for.

Cisco is committed to providing not only the best access points, client adapters, and bridges in the industry — it is also committed to providing a complete solution for any wireless LAN deployment. That`s why Cisco has the widest range of antennas, cable, and accessories available from any wireless manufacturer.

With the Cisco FCC-approved directional1 and omnidirectional2 antennas, low-loss cable, mounting hardware, and other accessories, installers can customize a wireless solution that meets the requirements of even the most challenging applications.

Jan 2003

  Amateur Antenna #1

This "15 minute antenna" is a quarter-wave ground-plane antenna with trough reflector formed on the end of 50 ohm coaxial cable with a light sheet metal trough type of reflector.

(Photo only) Estimated gain >8 dBi


  Amateur Antenna #2

A simple concept, the "circular waveguide antenna" is repeatable & easy to make with simple tools and without instruments.

These are often calculated and built as efficient amateur dish feeds. The dimensions given in the example offers 13.5dBi gain... with a beam-width approximately that required to efficiently illuminate a standard British satellite dish of f/D ratio = .72)

Radproject 2000


  Amateur Antenna #3

The simple 2.4GHz Double Quad Antenna is a compact and easy to make high performance antenna offering some 14.4dBi gain. As with the "circular waveguide antenna" type also on this page it offers a beam-width (in the vertical plane) not far off that required to efficiently illuminate a standard British satellite dish of f/D ratio = .72) The optimum reflector to element spacing requires a VSWR measurement system for a precise impedance match......


Mobile 2.4GHz Antenna
(23dBi Gain)

  Amateur Antenna #4

The European "ASTRA" Direct Broadcasting Satellite (DBS) pole mounted parabolic dish of 60cms dia. with an efficient ("double-quad") feed is capable of over 25dBi forward gain. Double Quad Feed

In this example the top stub mast is mounted on a standard Amateur Radio rotator made by Kenwood which motorises through 360 degrees rotation and the whole mast folds down into a "Rooftop Ski Box" on top of Amateur Radio vehicle G8OTA/M (mobile RV). (Pictures) double-quad.gif

July 2001


Double Quad (Bow Tie)

  Double Quad

* A compact directional antenna useful for workshop and hand-held operation
* Fair gain (14 dBi)
* Wide bandwidth (full 802.11b/g spectrum)
* More compact than Yagi or circular waveguide types of equivalent gain
* Fits a wide range of microwave cooking food containers
* Ideal as a feed to a standard domestic satellite dish
* Liberal mechanical tolerances
* useful as reference antenna
* Easy to replicate (- but do use correct gauge wire and thickest & best microwave coax you can afford !)
* Can use a 120mm CD as a reflector with slightly diminished performance at 2.4GHz
* Can omit the "Sleeve Balun" for ordinary Wi-Fi use
* Scalable for many frequencies
* See equally practical other variants on this page..

Originally from a German Amateur Radio Microwave Compendium design concept of the 1980's this
antenna concept has proven popular for broadband Amateur TV and I have made examples of these from 600MHz to 6GHz.

It exploits the 6dB gain from solid plane reflector (not everyone knows that ! )

Henry - G8OTA double-quad.gif

March 2008



A printed circuit 12 dBi version of the Double Quad, house in an ABS plastic case.

The AntCaptenna (ACA) was born from a desire to make an antenna that could be used as a 'client' antenna (i.e. used to connect to an AP) - had a reasonable gain (12-14 dBi) - was waterproof - was rugged - could be pole-mounted. The result was the AntCaptenna - which gets its name from the Ant-Cap used as the back reflector.

[Ant Caps are used on wooden stumps in Western Australia, to prevent white ants (termites) from coming up from the ground into the house.

Rob Clark

May 2003


  Adding an Antenna for DWL-650 PCMCIA card

a short guide to voiding your warranty by: Will Rachelson < will at c0rtex dot com >

The DWL-650

I purchased this card because it was the cheapest (<$100 @ CompUSA). I knew that I was going to build an antenna, but wanted to do so very cheaply. The connectors for the Lucent cards are costly and hard to find. There were some nice pictures at seattlewireless that convinced me it would be easy to add an antenna.


  Use a Surplus Primestar Dish as an IEEE 802.11 Wireless Networking Antenna

High gain from a simple DIY project. Uses a circular waveguide feed for illuminating a surplus Direct Broadcast Satellite (DBS) dish made here from a juice can and co-axial connector.....The author notes that the optimum length should be between 14 and 21 inches with the (can) opening at the focus of the dish. see Amateur Antenna #2 above


Bi-QUAD Dish Feed

Trevor Marshall

  Bi Quad Feed for Primestar Satellite Dish

Author: Trevor Marshall

"That's all there is to it, folks -- you now have a dish with 27-31 dBi of gain and negligable sidelobe radiation (<40dB). The beamwidth is about 4 degrees."

see below: WLAN Slotted Waveguide Antennas by the same authorTrevAuor


Central States VHF Society

Antenna Test Reports

  Central States VHF Society - USA

The Central States VHF Society has conducted Antenna Gain Measurements since its inception in 1967.

The published results can be used to make comparisons between commercial and homebrew antennas, between different homebrew designs, and between different commercial designs.

Comparisons can be made between antennas measured in different years on the 50 MHz through 432 MHz bands because the same reference antennas have been in use for over 10 years!

Nov 2004



  Design of a Planar Omnidirectional Antenna

Randy Bancroft and Blaine Bateman

March 2004


for 2.4GHz



A 6dBi Vertical Polarised Omnidirectional Antenna

An easy step-by-step guide go making a homemade wireless antenna, for a fraction of the cost of commercial antenna. Uses readily available parts, and requires no specialist tools or knowledge.Or in geek speak - an omnidirectional colinear dipole design suitable for wifi compatible hardware with external antenna connector.

Oct 2003



Double Quad type satellite dish feed design...

The Satenna is a complete unit: 65cm satellite TV dish, plus SatCap. The combined gain is 29 dBi.

You can make your own Satenna by simply buying or building a SatCap, and combining with a locally purchased satellite TV dish. Search your local 'Yellow Pages' for satellite TV installers for good prices on dishes and roof mounts.

Rob Clark

May 2003





Highest Performance Community WLAN Service Antenna for 2.4GHz

For best long range performance, horizontal polarization is a more effective polarization method. At 16dBi this antenna claims to be "the best omnidirectional horizontal polarisation service antenna available anywhere in the world"

Using new patented technology the "HS16" example offers a nominal all round 16dBi omnidirectional gain for general "point to multi-point service".

Using a pair of dual antenna access points these antenna each exhibit a sector gain of more than 20dBI (x 10 range) over a 90 degree sector, so that 4 of these antenna back-to-back at 90 degs (a Quad Block) more than cover a square service footprint with sides 20n x 20n where "n" is the normal isotropic antenna range...

It additionally features a directional peak 24 dBi ( x16 range) in one 15 degree sector for long range interlinking, obviating the need for an additional point-to-point dish up to 60cm dia.....see Field Plot

R.F. Termination = Silver plated "N Type" line socket Length = 1.8 metres. Weight = 7 Kg Mounting = 48mm dia.x 6mm thick walled aluminium stub. Casing White UPVC. Wind Loading Tested for 200 Km/h
Best VSWR = 1.04:1 (2445MHz)

This antenna is not yet commercially manufactured and distributed but can be supplied as "designer samples" individually hand made and tested at: $799 each.

Further details: A-Antenna Limited....


Vertically Polarised Omnidirectional
Co-linear ArrayAntenna

  Vertical Co-axial Sleeve Co-linear Array

A vertically polarised omnidirectional co-linear sleeve dipole array consisting of a number of stacked omni-directional elements.

with about 9dBi gain as shown.....

Radproject 2000


  Vertically Polarised 6dBi Co-Linear

You have seen them in catalogs for $150 to $250. Now you can build one for a fraction of the cost at the expense of some time. Construction time can take as little as a few days up to a few weeks, depending on your drive and resourcefulness. Proper acquisition of materials and the tools at your disposal will speed up the construction time. We will go over some theory, tools and materials required, construction steps for the feeble minded, installation tips, and our actual measured results. Construction of an assembly jig will also be covered for those that wish to mass produce a few of these for your community users. Everyone will need at lease one of these units for the multipoint location. Also for those who desire to provide access to a geographic location outside of their immediate locality.

The collinear antenna was historically used by repeater sites, stacking various 1/2 wave dipole elements on top of each other for increased gain connected by some equipment to correct for phase error between the elements of the array. The higher in frequency the better in gain you can achieve in a relatively small assembly. The eight (8) element array we build here will yield 6dBi gain in a radome of less than a meter.

  WLANAantenna 2.4 GHz Do-It-Yourself

"My antenna has found been about 2 dB better gain than the Freedom antenna, which is specificated as 12 dBi antenna."

( This >14dBi measured gain should make a good dish feed for an Ex-Astra European Satellite Dish.)

Martti Palomaki

11 July 2001


Circular Polarised Helical
Directional Antenna


Circular Polarised Helical Directional Antenna

A high performance circularly polarised directional antenna with a calculated gain of 18.2 dBi. Similar in concept to the Jason Hecker design also on this page..

W0OQC Feb 1998


  BLR-6GCC 2.4-2.5 GHz Ground Plane Antenna

BLR-6GCC is 4x5/8 vertical omnidirectional Ground Plane Antenna. The antenna's body is made of silver plated copper wire placed in the PVC radome. The feedpoint is a standard N female conector that is protected from the weather within the lower aluminum tube. A galvanized steel bracket provides easy side or top mounting to a 20-60mm dia. mast.

Horizontal radiation pattern is circular with 8.2dBi gain. Vertical radiation pattern is with downtilted lobes for good short and far distance coverage.

* Real 8.2 dBi gain .
* Downtilt mainlobe and sidelobe .
* Easy mouting .
* Excelent price/performance ratio .

Price US $150

Naugarduko 41 LT 2600 Vilnius Lithuania

Tel : +370 2 263068 Fax: +370 2 263668


  The "Truth" About Horizontally Polarized Omni-Directional Antennas

There are about 5,000 different antenna designs in existence. Of those 5,000 designs, horizontal omnis seem to be the one design most shrouded in mystery in the amateur radio world. UHF applications requiring horizontally polarized omni-directional antennas usually use an Alford Slot, its cousin the Rib-Cage Slot, or a loop antenna. Unfortunately, technical references containing slot antenna information rarely contain practical design information required to build such antennas reliably, and few experimenters have access to the resources needed to fully analyze the radiation properties of their antennas over wide bandwidths. A low VSWR is often mistaken as meaning an antenna is functioning well. However, VSWR means nothing when it comes to radiation patterns and antenna gain.


  Measured Performance Of The WB0QCD Alford-Slot Antenna

You've seen the ads. "5.6dBd gain...flat VSWR and good gain bandwidth performance over the entire 420-440 MHz band"... But just how well does the WB0QCD antenna perform in real life? We put ours to the test on a professional antenna range and the results we found were less than impressive! 

First, the good news. The WB0QCD Alford-Slot antenna is a mechanically solid antenna that does exhibit a horizontally polarized, omni-directional radiation pattern. The E-plane pattern is consistant with that of a single axially slotted cylindrical antenna with a small diameter/wavelength ratio (see G. Sinclair, "Patterns of Slotted-Cylinder Antennas" Proceedings of the IRE, vol. 36, pp.1487-1492; December, 1948). The antenna is about 3 dB more responsive in the direction of the slot than it is off the rear of the antenna. This feature is consistant across the entire 420 MHz to 450 MHz band.


  How to Make a Simple 2.425GHz Helical 
Aerial for Wireless ISM Band Devices

A comprehensive and well written DIY constructional article from Australia on making a 2.4GHz antenna with about a x 8 range magnification factor.......

(excellent case study example) 

Jason Hecker


  Improved Helical Antenna Design for 802.11b WLAN - by PA0HOO

The Disappointment
It was very disappointing to find out that 'the thingy' we made wasn't performing at all. Even the relatively small distance of 200 m could not be bridged. What was it that we did wrong??.

The dimension were OK, all sizes were according to the known formulas. The proven calculating programs such as helix_20 from  Holger Granholm and ‘HelixCalc’ from Jason Hecker gave similar dimensions.

The Experiment
We tried to find out the real 'over the ether' behavior of the antennas over a wide spectrum. We could use a cable TV spectrum analyzer up to 4 GHz and tracking generator up to 2450 MHz. Test area: our living room... 
We were astonished to discover that the antennas were radiating very well around 1650 MHz. 2450 was just outside the band pass. See the 'test set up' and the graph below. 

Detailed examination of the antenna design 

Looking into detail, there IS a difference between de ordinary Helix antenna and the PVC-one: The classical helix is al 'on air' spiral,  our spiral is 'on PVC'.  Kraus' formulas, calculate air spirals. As our spiral is on PVC, it COULD be that the traveling velocity of the radio waves inside the antenna is being influenced because of the high er of PVC. (similar to the cause of shortening factor of coax cables). In that case Klaus' formulas will give erroneous results. 

Detailed examination of the antenna design 

Looking into detail, there IS a difference between de ordinary Helix antenna and the PVC-one: The classical helix is al 'on air' spiral,  our spiral is 'on PVC'.  Kraus' formulas, calculate air spirals. As our spiral is on PVC, it COULD be that the traveling velocity of the radio waves inside the antenna is being influenced because of the high er of PVC. (similar to the cause of shortening factor of coax cables). In that case Klaus' formulas will give erroneous results. 

The main question is, could our PVC plumber tube actually cause the working frequency being decreased? If the answer is 'yes', it must be possible to improve the design. 

Study books say that the  traveling velocity is reversed proportional with the square root of the dielectric constant.

It appears that PVC has a fairly high dielectric constant.

Jan 2003



Visionary amateur microwave

broadband datacomms pioneer


.....some inexpensive antenna, radio, and computer interface hardware which allows communication of digital data at rates up to 2 megabaud (1 megabaud = 1 million bits per second) on an Amateur Radio band. The link operates in the 10-GHz Amateur band and uses an inexpensive commercial parabolic antenna along with a Doppler radar transceiver module to provide medium range communications at low cost. We'll discuss modifications to surplus networking interface cards that let you use this high speed data in Amateur Radio service with IBM-style personal computers. AX.25 packet radio has suggested the need for faster systems to improve current performance and has spawned some fundamentally new ideas for Amateur Radio. A whole spectrum of new user applications and the possibility of a nationwide or even worldwide digital Amateur network are two major areas made possible by faster hardware. 

Originally published in Ham Radio Magazine December 1989

(A great case study - applicable to current 100Mb and 1Gb DIY link development)

Frequency range 2400-2500 MHz
Gain: 14-17 dBi min
VSWR 1:1.5 (Referred to 50 ohm)
Beamwidth 30, 60o
Crosspolarization 22 dB

Linear Vertical
Dual Linear(+45,-45 deg)

Connectors SMA - standard. Other are optional
Fixed Tilt 0 - 10 o (optional)
Front to Back Ratio 20 dB
Power Handling 50 W per port
Mounting Pole mount/wall mount
(please specify at order)
  MARS Antennas & RF Systems Ltd. (Israel)


    MARS's 2.4 GHz PCS Antenna is designed for outdoor and indoor installations. The antenna is perfectly suited for all PCS wireless 2.4 GHz applications. In particular the antenna is exceptionally proficient in harsh outdoor applications. The combination of its aesthetic appeareance and high efficiency makes it ideal for installations where the antenna is installed at low heights.


Image of 30.jpg

  Pacific Wireless

Pacific Wireless manufactures high quality and low cost  wireless communications solutions for the 1.7 to 2.7 GHz  Frequency Bands, including MMDS, ISM (2.4GHz), DECT and S-Bands.

We offer parabolic grid directional antenna products and GaAs MMIC RFIC downconverter and mixer products targeted at the following  applications: Wireless Internet, Point to Point and Point to Multipoint..


Corner Reflector

Image of 31.jpg

  Parabolic AB

Welcome to Parabolic AB New! 2.4 GHz WLAN Antennas Parabolic has been into the cable- and satellite business since 1982 manufacturing satellite receivers, modulators, signal processors, antennas up to 8 meters and all kinds of accessories to...11/29/1999


Purdue University Group Project

  Purdue University - 2.45 GHz Yagi Antenna - Lafayette Indiana USA

Useful project to design a directional disc Yagi of17.5dB gain for

point to point WLAN applications.....

Has anyone a current link to this excellent project? ed.

Purdue University:

November 2004


SBISMSO5V - Vertically mounted suction cup 5dBi omni antenna for mobile and temporary non metallic mounting applications.

  Signull Technologies

We manufacture antennas and equipment for the 2.4ghz ism band used by 802.11b WiFi devices at competitive prices. You can check us out online.

Mike Spenard


  Model 2426AA WLAN 5 dBi Omni

This WLAN antenna is broadband and designed to operate from 2400 to 2483 MHz. The antenna features an omni directional pattern with a gain of 5 dBi. It is enclosed in a weatherproof radome for outdoor or indoor use. The antenna provides for mounting to a mast, or an optional ceiling mount is available. Standard coax connectors, as well as connectors to meet Part 15 of FCC regulations, can be supplied.

Wireless Internet Access in Latvia

Guntis Barzdins
Institute of mathematics and Computer Science, University of Latvia

Rainis blvd.29, Riga LV1459, LATVIA
Phone +371 9206943, Fax +371 7 820153, E-mail


The Latvian Research Network LATNET was established in 1992, shortly after breaking of the USSR. The limited resources and poor communications infrastructure in the country (only analogue lines available) have forced LATNET to search for alternative ways to establish high speed data links for Internet access to the numerous University of Latvia departments scattered around the capital city Riga. The liberal radio frequency licensing policy and newly appeared inexpensive and easy to use wireless LAN products, made it possible to develop a high speed spread spectrum wireless Internet access network. There are currently over 30 academic, research, government, and other sites - spread all over the city - using these high-speed wireless links for Internet connection as an alternative to lower speed leased telephone lines.

Guntis Barzdins


Image of 34.jpg


Licence free U-N11 100Mbps links at 5.5GHz. 

Providing Wireless Lan Equipment Solutions for Businesses.   ISPs, WIPOPs, 2.4GHz, 5.4GHz, Amplifiers, YDI: Wireless data solutions, Wireless LAN equipment, WANs, LANs, MANs, Broadband connectivity, wireless internet, Direct and Frequency Hopping Spread Specturm Equipment, amplifiers, antennas, modems, radio, ISA, PCMCIA, 2.4 GHz, 900 MHz, IEEE 802.11 




  HyperGain&trade; Model HG2415U

High Performance 15 dBi Omnidirectional Antenna

The HyperGain&trade; HG2415U High-Performance Omnidirectional Antenna features an impressive 15 dBi gain for long-range multipoint applications in the 2.4 GHz ISM band. 

This antenna’s construction features a lightweight fiberglass radome for durability and aesthetics. It’s mounting system features two heavy duty extruded aluminum brackets and stainless steel U-Bolts for superior strength in all-weather conditions.



  FERIMEX - Slovakia

Antenna Sector H4x90

12dBi Gain at 360 degrees with Horizontal Polarisation in four 90 degree sectors.

The H Range comprise 5 different Sector Antennas with horizontal polarization with different beam angles. For use as access point antennas. More expensive than vertical polarization antennas, use only when you need horizontal polarization.

The Antenna H4x90 has 4 connectors, one for each 90-degree sector, and requires 4 devices to be attached. In this way you can handle 4 times as many customers at one access point. Antenna H2x90 and Antenna H2x180 have 2 connectors and require 2 devices to be attached. Antenna H90 and Antenna H180 have one connector.

Oct 2007

  SuperPass Antennas Inc.

SuperPass Company Inc. was founded in 1996 by several world-leading electrical and electronic scholars and engineers who have a strong desire to develop innovative, high performance, and low cost antennas for the booming wireless communication industry.

Image of 37.jpg   TIL-TEK Antennas Inc.

.......provides a complete line of base station and remote antennas  in frequencies from 800 MHz to 5.8 GHz, with selected products  from 300 MHz to 28 Ghz. Applications include cellular, GSM,  PCS, DECT, WLL/WLAN and rural point-to-multipoint systems as well as special applications such as radar test targets and Digital Audio Broadcast antennas.

c. 1998


  WINNCOM TECHNOLOGIES 13.5 dBi Horizontal Omni

13.5 dBi Omnidirectional Antenna, Horizontally Polarized, 2.4 GHz
Product Code WRO2400-135H

Antenna Performance

Frequency 2.400 - 2.483 GHz
Gain (dBi) 13.5
VSWR >1.5:1
Polarization Horizontal
-3 dB Beamwidth 9
Impedence (ohms) 50
Maximum Power Rating 100 W

Physical Characteristics

Height 29.2 in. (737 mm)
Weight (Including Clamps) 2.5 lb. (1.46 kg)
Wind Load 125 mph (200 km/h)
RF Connector N type female
Mounting Stainless steel bracket set for Mast or Pole mounting 1.2 - 2.5 in (30 - 62 mm)



Image of 38.jpg


Prediction of wave propagation in indoor, urban and terrain scenarios. Wireless mobile communication networks incl. Radio network planning for macrocells, microcells, WLAN, indoor, Picocells.

  WLAN Slotted Waveguide Antennas

Unlike wideband antennas like the BiQuad, slotted waveguides are resonant antennas, and have a narrow operating frequency range. It is possible to increase the bandwidth, but at the expense of gain and radiation pattern. Highest gains are only achieved over a few channels of the 802.11b spectrum. This should not be a limitation in a fixed installation, as multiple antennas are typically deployed, each covering a few channels.The antenna can be "tuned" with adjusting screws, or by adjusting its length.
(if you need wide bandwidth then
the BiQuad is the better choice)

Author: Trevor Marshall

see above: Bi Quad Feed for Primestar Satellite Dish by the same author


Slotted Waveguide type for 11 -14dBi horizontal polarisation...

  Downpipe Antenna

Slotted Waveguide type for 11 -14dBi horizontal polarisation...

The downpipe antenna was born after seeing the success of the Trevor Marshall Waveguide (WG) design, but after frustration at trying to buy 'small' lengths of the required ALU tubing, at realistic prices. In Australia, the minimum quantity is 6 m - you normally need less than 1 m. A 6m length will not fit in a car, and costs AU$160.

However, 95 x 45 x 0.4 mm ZincAlum downpipe is readily available in any Australian hardware store, and a 1.8m length costs less than AU$ 9. While this material is much more 'flimsy', it turned out sufficiently strong enough that it did not distort when the slots were machined (my main concern), and was plenty robust enough to mount solidly with V-Clamps. The material itself is designed to be used outside - so corrosion is expected to be minimal.

Rob Clark

May 2003


  Horizontal Polarized - Wide-sector directional antenna.

A typical amateur constructed high performance wide sector directional antenna based on a slotted waveguide design by DL4EBJ


Horn Antenna

  TDK RF Solutions Inc

"The TDK HRN-0118 broadband horn antenna is designed specifically for radiated emissions and immunity measurements in EMC test environments. The HRN-0118 horn antenna provides optimal performance over the frequency range of 1-18" GHz.

The HRN-0118 generates high electric fields required for radiated immunity and emissions EMC test measurements, and features high gain, low VSWR, moderate power handling (500W), broadband range, and a robust mechanical design."

Mechanical Specifications
Overall Size:
Width: 23.4 cm (9.21 in)
Depth: 29 cm (11.54 in) with mounting bracket ; 21 cm (8.27 in) without bracket
Height: 14.5 cm (5.71 in)
Weight: 1.9 kg (4.2 lbs) with mounting bracket

Dec 2014


USB adaptors
& DIY antennae

"Poor Man's WiFi" ?

  USB adaptors & DIY antennae "Poor Man's WiFi" ?

Harbour 10Km Link

A popular site with lots of imaginative and interesting low cost antenna ideas for DIY antenna from Massey University New Zealand.... Frying pans, Cooking Woks, foil and mesh lined Umbrellas.

"Gains typically ~12-15db with LOS ranges ~3-5km, AND great cost benefits from using cheap RF loss free USB cable" (repeater cables every 5metres length)

Stan Swan
Wellington, New Zealand

Oct 2005



What is Wi-Spy™?

Wi-Spy™ is the world's smallest 2.4 GHz spectrum analyzer*. Wi-Spy is
perfect for troubleshooting interference from the following devices:

  • Wi-Fi (802.11 b/g/n)
  • Microwave Ovens
  • Cordless Phones
  • Baby Monitors
  • Bluetooth

Wi-Spy is a fraction of the cost of traditional spectrum analyzers!
*Wi-Spy's frequency range is 2.400 - 2.483 GHz



Slotted Waveguide Antenna


CREVICE Z-17 Super High Gain
16.5 dBi Omnidirectional High Gain Antenna

Outdoor design
gold elements.

Electrical Specifications:
Gain (at work with other antenna working in horizontal polarization) 16,5 dBi
Frequency 2400 - 2500 Mhz
VSWR 1,3
Polarization horizontal
Vertical beamwidth E vector 8
Horizontal beamwidth horizontal H vector 360 (dokladnie 2x160 -3dB)
Termination / connector N-type / female
Impedance 50 Ohm
Weight 2 kg
Dimension length 860 mm, section 100x50 mm  
Clamp (Mounting bracket) 30-60mm


Dec 2007


Image of home3_b.gif

  Click on the headings below

Image of 18.jpg   BreezeCOM

The AMP-500, 500 mW amplifier (after-burner) is used to increase the range of outdoor links. Its built-in 3.5dB Noise Figure Receiving Amplifier can also be used to compensate for cable losses to an antenna at the top of a building or mast.



  Linksys Wireless Booster

The Linksys Wireless Signal Booster piggybacks onto your Linksys Wireless Access Point (or Wireless Access Point Router) to increase the effective range and coverage area of the 802.11b network.

  • Increase the effective range of your Linksys 802.11b Access Point or Wireless Access Point Router
  • Stronger signal improves throughput by reducing retransmissions
  • Save on wiring costs -- increase your Access Point's coverage into hard-to-reach areas
  • Simple installation -- stack, connect, and go




The ILB30-24 is an industrial quality outdoor RF Power Amplifier. From the Middle East to Anchorage, Alaska, its rugged, weatherproof design allows the ILB30 to survive in extreme outdoor environments.

Each unit is tested 3 times before being shipped. An assembly line ON/OFF Test is followed by an RF Power Output Test, and then finally with an RF Power Consistency Test. There is no better performing, or higher quality Outdoor RF Power Amplifier than the ILB30-24.

The amplifier comes complete with the DC power injector module (INJ24) as well as the 12V AC Power Adapter.


  • Dual Band b & g Compatible
  • Rugged Outdoor Housing
  • Low Heat Generation
  • Clean Signal Gain
  • Low Noise Floor
  • Plug-n-Play Ready
  • Complete with Power Supply


SKU RNS-ILB30 Weight 3.05 lbs



We are pleased to offer four power amplifiers for the 2304 - 2450MHz. amateur radio bands. 

Three 5 watt models are offered with various gain configurations as well as a 10 watt 10dB gain model. Commerical wide band versions as well as custom frequencies are available. Call us with your requirements. 


Small mechanical dimensions. Commercial construction in a milled aluminum case
Built in detector for monitoring power output. SMA - Female connectors
10 or 27dB Gain (Depending on model). 13.8VDC operation
Small size 80 x 60 x 20mm ..... 130 x 60 x 20 mm

Built-in protection for the Power GaAs FET


  Model WL-2400A .5 Watt IEEE 802.11 Mast-mounted 2.4GHz. Wireless LAN/WAN Amplifier

Ultra Low Noise Preamplifier, automatic RF carrier detection, plus a CDMA rated linear amplifier operating at less than .3dB compression all add up to solid links over extended distances. The WL-2400 A is the highest performance LAN amplifier available today!

.5 watt RF output 10dB Transmit Gain
Preamplifier NF <1.5dB Preamplifier Gain 14.0dB typical
Seamless interface to all LAN cards Suitable for land, mobile, aircraft and shipboard use
IEEE 802.11 compatible Rugged mast-mounted 100% weatherproof construction
Heavy Duty "N" type connectors 120V / 220V AC or 13.8VDC operation

  Hyper Amp II Model 2401

1 Watt IEEE 802.11 compatible 2.4 GHz Wireless LAN Amplifiers HyperAmp&trade; II is the latest evolution in HyperLink’s family of pole-top amplifiers for spread spectrum wireless LANs. This unit’s high power, high gain and ultra-low 2.5 dB noise figure make it the highest performance wireless LAN amplifier available today.

The HyperAmp&trade; II significantly improves operating range and link reliability by placing maximum transmit power and up to 20dB of receive gain directly at the antenna where is most effective. The unit can be configured to deliver over 1 Watt of transmit power with as little as 1mW of input power. This feature permits cable runs of several hundred feet with no degradation


40 Watt 2.4GHz Amplifier



Dec 2004


Image of home3_b.gif

  Click on the headings below