Earth Observation Satellite 1700 MHz Patch Antenna

The L-Band is carved up for many services and the 1690 to 1710 MHz Space to Earth band is shared with 4G cell phone services, with several geo stationary and polar orbit earth observation satellites operating at 1702.5 and 1707 MHz. Since I recently made an ADS-B 1090 MHz patch I decided to make one for this higher frequency band, while I am still in the swing of things with my mad antenna carving skillz.

This Right Hand Circular polarized antenna is carved from Rogers RO4350B low loss PCB and after a couple days of meticulous cutting and measuring it is spot on.

It is amazing what one can make if one has enough coffee, chocolate and patience!

Rogers 4350B copper clad circuit board has the following RF parameters:

Permittivity Dk = 3.66
Loss Df = 0.0031
Dielectric width Dw = 0.508 mm
Cu 1 Oz = 36 um

This Joint Polar Satellite Service (JPSS) antenna has the following dimensions:

Base: 69 x 54.6 mm
Patch: 53.3 x 43.4 mm
Corners: 12 x 12 mm
Slots: 5 x 8 mm
Feed: 1.1 x 7.5 mm

A receive antenna does not have to be super accurate, but 0.1 mm makes a measurable difference. If you have very steady hands, a sharp scalpel, calipers and a reasonable quality Vector Network Analyzer, then you can carve one of your own and see what you get, or you can send me a message and once there are multiple takers, I'll have a batch made at Eurocircuits, next door in Hungary.

La voila!

Herman

Comments

Parasitic Quadrifilar Helical Antenna

This article was reprinted in OSCAR News, March 2018: http://www.amsat-uk.org If you want to receive Satellite Weather Pictures , then you need a decent antenna, otherwise you will receive more noise than picture. For polar orbit satellites, one needs an antenna with a mushroom shaped radiation pattern . It needs to have strong gain towards the horizon where the satellites are distant, less gain upwards where they are close and as little as possible downwards, which would be wasted and a source of noise. Most satellites are spin stabilized and therefore the antenna also needs circular polarization, otherwise the received signal will flutter as the antennas rotate through nulls. The helical antenna, first proposed by Kraus in 1948, is the natural solution to circular polarized satellite communications. It is a simple twisted wire - there seems to be nothing to it. Various papers have been published on helix antennas, so the operation is pretty well understood. Therefore,

Weather Satellite Turnstile Antennas for the 2 meter Band

NEC2, 2 m band, 146 MHz, Yagi Turnstile Simulation and Build This article describes a Turnstile Antenna for the 2 meter band, 146 MHz amateur satcom, 137 MHz NOAA and Russian Meteor weather satellites. Weather satellite reception is described here . A quadrifilar helical antenna is described here . Engineering, is the art of making what you need, from what you can get. Radiation Pattern of the Three Element Yagi-Uda Antenna Once one combine and cross two Yagis, the pattern becomes distinctly twisted. The right hand polarization actually becomes visible in the radiation pattern plot, which I found really cool. Radiation Pattern of Six Element Turnstile Antenna Only a true RF Geek can appreciate the twisted invisible inner beauty of a herring bone antenna... Six Element Turnstile Antenna Essentially, it is three crosses on a stick. The driven elements are broken in the middle at the drive points. The other elements can go straight throug

Patch Antenna Design with NEC2

The older free Numerical Electromagnetic Code version 2 (NEC2) from Lawrence Livermore Lab assumes an air dielectric. This makes it hard (but not impossible) for a radio amateur to experiment with Printed Circuit Board Patch antennas and micro strip lines. Air Spaced Patch Antenna Radiation Pattern You could use the free ASAP simulation program , which handles thin dielectrics, you could shell out a few hundred Dollars for a copy of NEC4 , You could buy GEMACS if you live in the USA, or you could add distributed capacitors to a NEC2 model with LD cards (hook up one capacitor in the middle of each element.), but that is far too much money/trouble for most. More information on driving an array antenna can be found here: https://www.aeronetworks.ca/2019/03/driving-quad-patch-array-antenna.htm l Air Dielectric Patch The obvious lazy solution is to accept the limitation and make an air dielectric patch antenna. An advantage of using air dielectric, is that the antenn

Aeronetworks sro - Airborne Linux

Search This Blog