Hi, I want to know what is the relation between output frequency and transmitting power of any transceiver IC.For the case-
1) What will be transmitting power output if my frequency is 300 MHz.
2) What gain margin is will justify my power amplifier to approach the power of 40 dBm (10 watts)
It will be really helpful if you guide me the process and criteria of selection of Power amplifier in case of RF.
1) Please refer to the datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD9361.pdf
See figures 16, 42, 63. These are representative numbers that you can expect. For your device at the desired frequency, running a one-tone test with the help of a physical hardware test equipment such as a spectrum analyzer is an approach to get exact numbers.
2) What gain margin are you referring to? The standard calculation is, If P_out at 1dB input backoff (IBO) of your power amplifier is 40 dBm, then
40 = G + P_in -1
If the PA is operated in its linear region, 40 = G + P_in
As an example, if the gain of your PA is 40 dB, you would need 1 dBm input power to generate 40 dBm output power. Of course, the PA is operating in non-linear region and your signal will contain the corresponding artifacts. With respect to AD9361, you need to make sure to select a PA such that it's G gives you the desired P_out since P_in is a fixed number for your device at a desired frequency.
Thanks for sharing such information. Have understood the P_out, P_in, gain relation and how to calculate them.It will be also helpful if you share what is the actual relationship between my frequencies.For example, in case of AD9361 maximum transmitting power is 19dBm @900MHz. How my frequency will be related (decreased) if i will use a further PA whose output may go range 30-40 dBm following desired P_in and gain range ?(Note- i can compromise my output frequency since working at VHF Band).
If you can share some PA which can increase my output up to 5-10 watts(37-40 dBm) @300 MHz from transceiver AD9361.
As mentioned earlier please refer to the datasheet graph.
For PA recommendation please post your query in the below forum,