Need help with designing a wireless circuit

[almie]

wireless circuit

plis help me on

wireless mic with performance

FC : VHF 210 ~ 270 MHz
dynamic range : ≥90 dB
freq response : 40 Hz ~ 15 KHz ±3dB

receiver circuit that have specification as below:

power : DC 17V 200mA
snr : more than 90 dB
receiving sensitivity ; 10dBuV
deemphasis : 50 us

tx circuit with spec:

power : 8.5 mW
modulation FM
max deviation : +- 25 kHz

 

[Borber]

Re: wireless circuit

Specifications are OK.
What do you want?

 

[throwaway18]

Re: wireless circuit

90dB of audio dynamic range will be very difficult to do and you will only get that when you have a strong rf signal reaching the receiver and low interference.

You need to descide if it is going to be manually tuned, crystal controlled or synthersized.

If you have a license for a paticular frequency then you will need to be very close to the correct frequency, perhaps +/- 1KHz. In that case you need either a crystal controlled transmitter or a frequency synthersizer.

If you make it manually tuned (LC oscillator) then you will have to consider frequency stablility with temperature, supply voltage and time.

There are lots of books about superhetrodyne radio receivers.

Added after 10 minutes:

Depending on your application it might be acceptable to put a compressor on the audio input.

 

[almie]

Re: wireless circuit

thank you for the explanation but i dono to build the circuit...any guidance..