Re: Need help with 434MHz receiver circuit explenation!
Thanks again for your reply :) I just measured my transmitted signal occupied bandwidth (OBW) and it's about 500kHz.
Sorry, that I nevar indicated my signal, yes, you are correct, it's train pulse, and its frequency is from 10Hz - 1kHz. But like I mentioned before, this train pulse is ansynchronous, becouse I have rule to design asynchronous data acquisition and transmission without any clock (clk). So I try to find way to transmit 10 or more (in future even 60) channels using asynchronous data transmission.
Can you suggest me something? Also, tell me more about how can I transmit these asynchronous data with digital method? Is it possible?
Also can you give me some examples, literature, circuits with transmitter where is used coaxial filters?
About SAW filters I will read this publication to understand if I could tune its frequency.
And how about replacing SAW resonator with LC contour?
Best regards,
Kaspars
Transmitting the signals by 10 independent modulators sounds like a reminiscence to 60th or 70th electronics, times when digital signal processing wasn't yet available with affordable effort. Digitizing the signals would be in fact an obvious state-of-the-art solution. But it involves quantization and demands to think about the significance of signal timing information and required resolution.
If you plan to transmit a time critical asynchronous signal, and as any coding & decoding cost time, adds uncertainty and a radio signal have limited bandwidth, what is your timing requirement in this project? Is it mS, uS? Selection of radio type, bandwidth and modulation are secondary questions until you know what base-band data you have to transfer.
According to your photo is the antenna wrong mounted. It can not have ground-plane below it.