Compact Gain Measurement Chamber: 100x smaller & cheaper than conventional anechoic chamber! скачать в хорошем качестве

Compact Gain Measurement Chamber: 100x smaller & cheaper than conventional anechoic chamber!

Poynting is evaluating an extremely compact (1m3) and low cost (less than $2000 excluding single port network analyser) chamber for measuring antenna gain in the 700MHz to 6GHz range. The chamber is intended for doing QA measurements of gain at our Chinese factory in addition to current reflection loss QA checks. The chamber only requires a single port complex network analyser to measure reflection coefficient (S11/ impedance/matching). Gain measurement normally requires two port (S12) measurements since it involves measuring signal between a UAT and reference antenna. This chamber overcomes this problem by using a rarely used gain method called the One Antenna Method. The AUT is placed facing a reflector creating an identical "image" antenna and comparing the reflected signal with (Sr) and without this reflector (Sf) one can extract the portion contributed by the "image antenna"/reflection" (Si) by complex subtraction: Si = Sr-Sf and consider this as the "receive signal". A single port device can be used to obtain Sf and Sr and gain obtained using fairly similar equation to the normal link equation. The chamber makes minimal use of RF absorbers and separate out reflections by converting the signal to the time domain using inverse FFT (IFFT) operation and then use time gating to minimise both the large mismatch reflection from the AUT (happens earlier than Sr) and then also cutting out reflections which occur after reception of the desired Sr since such reflections occur considerably later due to the close spacing (1m) between the AUT and reflector (giving a signal path of 2m) while external reflections (roof/floor and other objects) typically will travel around 5m or longer allowing them to be "gated" out in the time domain and then do another FFT to obtain a "cleaned up" gain vs frequency This Compact Gain Measurement Chamber forms part of the 4th year electrical engineering lab of David Curtiss and George Philips. They are students at WITS University and this project was sponsored by Poynting Antennas. Want to talk to someone at Poynting contact us here: South Africa: +27 12 657 0050 or info@intetoconnect.co.za Europe: +49 89 7453 9002 or sales-europe@poynting.tech USA: +1 817 533-8130 or sales-us@poynting.tech Rest of the world: +27 12 657 0050 or sales-global@poynting.tech Website: https://poynting.tech/