How can I test active integrated oscillator antenna

[Lathas]

How can I test an active integrated oscillator antenna, where the antenna acts as a freq selective part for the feedback oscillator?

 

[D.A.(Tony)Stewart]

How can I test an active integrated oscillator antenna, where the antenna acts as a freq selective part for the feedback oscillator?

You can't test it with a design spec , then a plan and finally the equipment to perform it.

 

[jiripolivka]

Depends on what you need to test. Integrating an oscillator with an antenna combines the features of both. The output frequency can be affected by close objects as well as the radiation pattern.

To test, one needs a spectrum analyzer with a simple antenna like a dipole or horn,to measure the output frequency, its stability and radiation pattern.
Also polarization can be measured this way, and the output power over a specified distance (propagation loss included).

 

[vfone]

Some of the active integrated oscillator antennas use the antenna on the feedback path of the oscillator, but some of them don't and the antenna is just coupled to the oscillator (E-plane or H-plane).

 

[biff44]

oscillators get their "goodness" from how decoupled they are from their loads. So by design one often deliberately sacrifices output power for more stability by decoupling the oscillator from the load.

In your case, maybe a series reactance between the oscillator and antenna input helps to do that.

BUT, if the frequency determining element of the oscillator is the antenna itself...then the oscillator's frequency, noise, output power, etc will be STRONGLY determined by what is near the antenna. For instance, put your hand near the antenna, and the frequency moves.

so a test might be how much the frequency moves due to loading effects. You could hook up a horn antenna 4 inches away that has an attenuator (like 3 dB) and then a sliding short, and move the sliding short around and see the +/- frequency change. You could use the same setup with a directional coupler to figure out transmitted power. Then you could adjust the oscillator coupling to balance the two.