It seems that the question is very general. Usually, we have to consider 2 types of measurement: the one you do indoors, e.g in anechoic chamber while others can be done outdoor, free space especially if the AC dimensions do not allow you to measure precisely the antenna parameters; here we shall consider the frequency range that interests you.

In case you have to measure the antenna in AC, you have 3 methods. Could you please let us know whether the antennas in Tx and Rx are the same so maybe I can focus my answer.

You can do it if you have anechoic chamber and signal generator otherwise you cannot

Dear Logan,

The first thing you need to do is to simulate the antenna first before doing any kind of mesurement. Once complete, you can proceed with measurement. What are you expexting from your antenna actually?

Dear Logan,

For a professional indoor measure you need an anechoic chamber, a signal generator, a calibrated receiving antenna, and a receiving device such as a power meter or a spectrum analyser. If the working frequency is quite low you can measure the beam pattern considering two mechanical supports with the RX and TX antenna placed at a given high from the ground and find the so called Fresnel ellipsoid. Since at low frequency it is hard to find chamber of big dimensions.

However if you want to perform a roughy measurement you must simulate as better as possible the free space condition for example choose an open field (a football field could be perfect) two dielectric pedestal for example made of wood, as reference antenna you can use a dipole antenna easy to made, simulate and calibrate, if you have a portable spectrum analyser you can use it as receiver. Once for a roughly measure of a beam patter i used a portable spectrum analyser at span zero and a servo motor for change the antenna direction.

If you don't have a spectrum analyser and the signal is sufficiently high you can use a crystal detector ( but the signal must be quite high).

You must specify what kind of measure you require, high accuracy or not, the working frequency and the antenna kind.

Dear logan,

Here measurement is done in 3 categories, Near Field Reactive,Near field radiating and Far field.

Yes, First you have to measure Return loss of antenna, VSWR plot and then go for the GAIN measurement.

Hope you get my point.

In case you still have doubt then you can explore it here.

Have you found out how to measure radiation pattern for SONAR application? It has to be different from that for free space measurement. If you are still interested, we can discuss. Mail me at [email protected]

As far as I understand you have to construct an accoustic antenna.

You can use the analogy between acoustic and electromagnetic phenomena. With regard to the electromagnetic antennas can be said the following.

Restrictions on the dimensions of the conventional test may be reduced by making measurements of the antenna's near-field.

Further application of analytical methods allows transformation of these measurements into antenna's parameters such as radiation pattern, gain etc.

This method is much more cost effective than the conventional method, but it is rather complex.

Yes you can do it with anachoeic chamber and signal generator.

Use a simple spectrum analyzer ( with needed frequency range) and a signal generator. you also need a rotatable mount so that u can check the pattern at all the direction.

now your transmitting antenna could be a directional antenna ( horn antenna would do). connect your transmitter to signal generator.

connect the receiver antenna (antenna to be tested) to spectrum analyzer via rotatable mount. keep the distance between tx and rx equivalent to far field distance.

Adjust your frequency in both sig generator and spectrum analyzer. check the peak value of the spectrum for ever angle (rotatable). Note these values plot them using mat lab or either use radar plot of word.

This website might help: http://www.antenna-theory.com/measurements/radpattern.php

You can measure the radiation pattern without anechonic chamber too. However, the radiation pattern become too erratic. I have seen some article did without the chamber. However, you need a kit to do that. I have been using MAN TEL radiation pattern plotter kit. It has a variable frequency at 3 to 4 GHz and 5 to 7 GHz. But, accuracy wise I prefer chamber. But, not all university can afford for a chamber. Thank you

For more accurate result: anechoic chamber, but it is costly. Other alternative like the use of module, etc, cheaper but less accurate and limited measured frequency (spec. Dependant)

For cheaper and less accurate result you can use EMScan module. Reasonably okay for small size (microstrip) 800MHz to 6GHz antenna.

Professionally, you need an anechoic chamber..with other stuff like spectrum analyzer, signal generator, e.t.c. However, many institutions lack these expensive systems...so if available, ED Antenna Trainer Kit is an option but limited to 500MHz to 10GHz.