Salvador12
Full Member level 4
I ask this mostly about the small radar "detectors" receiver units used in cars for police radar but I suppose this also applied to larger radars.
Is it possible to have a radar receiver that doesn't leak it';s own Local Oscillator frequency at all?
I understand that in heterodyning you always have to use a local oscillator and then to mix the output of it with the incoming radio wave in order to get some IF frequency which can then be amplified and the output checked whether it is in the known radar bands to give a result (beeping etc)
Is it true that in the cheapest radar receivers they simply use the antenna itself as the mixer? They just dump the LO output to the antenna and then let the incoming radio wave and the LO driven signal overlay within the antenna?
I see from block schemes that in the more expensive ones they use a separate mixer and before the mixer /right after the antenna is a separate RF amplifier, does this RF amplifier work like a buffer so that any leakage from the mixer can't simply end up int he antenna ?
Is it possible to have a radar receiver that doesn't leak it';s own Local Oscillator frequency at all?
I understand that in heterodyning you always have to use a local oscillator and then to mix the output of it with the incoming radio wave in order to get some IF frequency which can then be amplified and the output checked whether it is in the known radar bands to give a result (beeping etc)
Is it true that in the cheapest radar receivers they simply use the antenna itself as the mixer? They just dump the LO output to the antenna and then let the incoming radio wave and the LO driven signal overlay within the antenna?
I see from block schemes that in the more expensive ones they use a separate mixer and before the mixer /right after the antenna is a separate RF amplifier, does this RF amplifier work like a buffer so that any leakage from the mixer can't simply end up int he antenna ?