Patent ID: 9698911
Date: 2017-07-04
CPC Classifications: H04B

Claim:
1. A communication device for radio frequency (RF) downconversion, the communication device comprising: a laser; a local oscillator; a first electro-absorption modulator coupled to the laser to receive an optical signal from the laser, the first electro-absorption modulator configured to convert a received RF signal into the photonic domain by modulating the received optical signal based on the received RF signal to output a modulated optical signal; a photonic filter coupled to the first electro-absorption modulator to receive the modulated optical signal output by the first electro-absorption modulator, the photonic filter being configured to output a filtered optical signal based on the received modulated optical signal; a first combiner coupled to the photonic filter to receive the filtered optical signal from the photonic filter, coupled to the laser to receive the optical signal from the laser, and coupled to the first photodiode to output a signal based on the filtered optical signal and the optical signal; a first photodiode coupled to the photonic filter to receive the filtered optical signal from the photonic filter, the first photodiode being configured to convert the filtered optical signal into the RF domain to output a filtered RF signal; a second electro-absorption modulator coupled to the laser to receive the optical signal from the laser and coupled to the local oscillator to receive a LO signal from the local oscillator, the second electro-absorption modulator configured to convert the LO signal into the photonic domain by modulating the received optical signal based on the received LO signal to output an LO modulated optical signal; a photonic service filter coupled to the second electro-absorption modulator to receive the LO modulated optical signal output by the second electro-absorption modulator, the photonic service filter being configured to output a filtered LO optical signal based on the received LO modulated optical signal; a second combiner coupled to the photonic service filter to receive the filtered LO optical signal from the photonic filter, coupled to the laser to receive the optical signal from the laser, and coupled to the second photodiode to output a signal based on the filtered LO optical signal and the optical signal, wherein the first and second combiners are separate from each other; a second photodiode coupled to the photonic service filter to receive the signal based on the filtered LO optical signal and the optical signal from the second combiner, the second photodiode being configured to convert the filtered LO optical signal into the RF domain to output a filtered LO signal; an RF mixer coupled to the first and second photodiodes to receive the filtered RF signal from the first photodiode and the filtered LO signal from the second photodiode, the RF mixer configured to mix the filtered RF signal and the filtered LO signal to downconvert filtered output and generate an intermediate frequency (IF) signal.