Hi, I am hoping to detect the phase difference from a 433.92MHz carrier signal detected at two antennas, where one antenna is about a 1/4 wavelength further from the transmitter than the other.
The circuit looks as follows in quote. I use PLLs to ensure phase lock on the carrier and pass the 2 signals to a phase detector:
My questions are:
1) Do I really need the PLLs? Can I just put the antenna signals into the Phase difference detector without phase lock, or do I really need the VCO (powered) output?
2) If PLLs needed, what ICs do you recommend? Do I need special PLLs capable of locking onto a 433.92MHz signal? Or can I somehow use standard 4046/LM565??
3) What IC for final phase comparator? Anything special required?
I hope you can answer my questions!! If you can, then you have probably guessed that the circuit is designed to detect which antenna is closest to the transmitter source, within a wavelength as per diagram in quote:
Antennae are about a foot apart.
HOPE YOU CAN HELP!!!!!
The circuit looks as follows in quote. I use PLLs to ensure phase lock on the carrier and pass the 2 signals to a phase detector:
I hope you can understand my circuit diagram. A second Bandpass filter after the BJT Amps would double the 6dB of the first to 12dB, so I will probably put those in each line aswell.(Antenna 1) (Antenna 2)
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(JFET AMP 1) (JFET AMP 2)
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(~433.92 MHz Bandpass 1) (~433.92 MHz Bandpass 2)
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(BJT AMP 1) (BJT AMP 2)-
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(PLL1) (PLL2)
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|-----------------------------------------|
|
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(PHASE COMP )
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OUTPUT
My questions are:
1) Do I really need the PLLs? Can I just put the antenna signals into the Phase difference detector without phase lock, or do I really need the VCO (powered) output?
2) If PLLs needed, what ICs do you recommend? Do I need special PLLs capable of locking onto a 433.92MHz signal? Or can I somehow use standard 4046/LM565??
3) What IC for final phase comparator? Anything special required?
I hope you can answer my questions!! If you can, then you have probably guessed that the circuit is designed to detect which antenna is closest to the transmitter source, within a wavelength as per diagram in quote:
Antenna1
.
. ---- ------------------------------------------------------ Transmitter
.
Antenna2
Antennae are about a foot apart.
HOPE YOU CAN HELP!!!!!