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Best tools for analysing Receiving (Active) Antennas?
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tautech:

--- Quote from: vinlove on January 26, 2023, 09:18:51 pm ---To reiterate the OP,

1. Is it possible to analyse Rx antennas especially the active antennas for the resonance and efficiency for the given band or frequency using measuring equipment or tools such as NanoVna or Tiny Spectrum Analyser?

2. If it is, then what would be the parameters? - What are we measuring and against what etc?

3. Which tester / measuring tool would be best for the job?

--- End quote ---
Which could be frequency dependant as AFAIK these cheap devices use a square wave for their stimulus.

Best tool = proper VNA.
Bud:

--- Quote from: nctnico on January 26, 2023, 01:51:07 pm ---Are you sure that using two identical antennas will work? From what I've read, antennas may have different RX & TX gains so splitting the result in half won't work. A while ago I found a paper from R&S on this subject and they proposed a method where you use 2 different antennas in 4 different combinations in order to get to the RX & TX gain of each antenna.

--- End quote ---
This is weird. Antennas are reciprosal devices, that is - have exactly same charactristics in transmit vs receive. Any pointer to the article?
tautech:

--- Quote from: vinlove on January 26, 2023, 09:18:51 pm ---To reiterate the OP,

1. Is it possible to analyse Rx antennas especially the active antennas for the resonance and efficiency for the given band or frequency using measuring equipment or tools such as NanoVna or Tiny Spectrum Analyser?

2. If it is, then what would be the parameters? - What are we measuring and against what etc?

--- End quote ---
We'd use just 2 related measurements to initially quantify an antenna, Mag Loss and SWR.
From there we might use a Smith chart measurements and adjustments to get the best 50  \$\Omega\$ impedance match for the passive part of the antenna. Any active parts would be analysed differently which for a 2 way active device would require S11 and S21 measurements.

Again you've given us no idea of the frequency you need to cover or anything in the future you might want to work with, say 900 MHz LoRa or 2.4, 5 GHz WiFi ?
Bud:

--- Quote from: vinlove on January 26, 2023, 09:18:51 pm ---To reiterate the OP,

1. Is it possible to analyse Rx antennas especially the active antennas for the resonance and efficiency for the given band or frequency using measuring equipment or tools such as NanoVna or Tiny Spectrum Analyser?

2. If it is, then what would be the parameters? - What are we measuring and against what etc?

3. Which tester / measuring tool would be best for the job?

--- End quote ---
1. I do not see why not, if those toys you mentioned have sufficiently small frequency step size and output not exceeding the antenna's max input level (also see #3)
2. Just like with a passive antenna, you sweep the given frequency range with frequency increment and amplitude from #1
3. This is where the problem is. With a passive antenna you just connect a VNA to the antenna's terminals. With an active antenna you can't because there is the amplifier in between. In general, you'd connect the VNA to a separate transmitting antenna with a wider bandwidth, and locate your active antenna some distance away. The testing tool here is a generic VNA with step size small enough to capture the tested antenna resonance and with output power (taking in account the transmitting antenna's gain and distance to the receiving antenna) not exceeding the receiving antenna's max input power.
nctnico:

--- Quote from: Bud on January 26, 2023, 10:41:58 pm ---
--- Quote from: nctnico on January 26, 2023, 01:51:07 pm ---Are you sure that using two identical antennas will work? From what I've read, antennas may have different RX & TX gains so splitting the result in half won't work. A while ago I found a paper from R&S on this subject and they proposed a method where you use 2 different antennas in 4 different combinations in order to get to the RX & TX gain of each antenna.

--- End quote ---
This is weird. Antennas are reciprosal devices, that is - have exactly same charactristics in transmit vs receive. Any pointer to the article?

--- End quote ---
Look at discone antennas.
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