Patent application number | Description | Published |
20100093297 | FM RECEIVER - FM receiver including an RF input circuit followed by a tunable mixer stage for frequency conversion of an RF FM signal into an IF FM signal, which is coupled to an FM input of a first narrow-band IF filter. The center frequency of the first narrow-band IF filter is controlled to vary in dependence on the IF FM signal. The first narrow-band IF filter is subsequently coupled to a first FM demodulator and a first LF signal processing unit. To increase the receiver's selectivity and sensitivity without adversely affecting tracking stability, the FM input of a first narrow-band IF filter is coupled through a second FM demodulator to a control input of said first narrow-band FM tracking filter for a feed forward tracking control of the center frequency of said first narrow-band FM tracking filter with the momentary frequency of the IF FM signal. | 04-15-2010 |
20100265116 | ANTI JAMMING SYSTEM - Anti jamming system comprising a tunable negative jamming signal feedback loop for feedback suppression of a received jamming signal, including an receiver receiving an jamming signal followed by a replica jamming signal generator for generating an replica jamming signal. The receiver comprising a zero IF PLL receiver having a synchronous demodulator and a phase detector, signal inputs thereof being coupled to said input means and carrier inputs coupled to in-phase and phase quadrature oscillator outputs, respectively, of a local voltage controlled oscillator (VCO), said VCO receiving a tuning control signal for tuning the zero IF PLL receiver at the carrier frequency of the jamming signal. The VCO is included in a phase locked loop (PLL) comprising subsequent to the VCO, said phase detector and a loop filter. The replica jamming signal generator includes a modulator with a baseband signal input coupled to an output of said synchronous demodulator and a carrier input coupled to the in-phase oscillator output of the VCO, an output of said modulator being negatively fedback to the input of the receiver. | 10-21-2010 |
20100283658 | ANTI JAMMING SYSTEM - Anti jamming system comprising a tunable negative jamming signal feedback loop for feedback suppression of a received jamming signal, including a receiver receiving an jamming signal followed by a jamming signal replica generator for generating an replica jamming signal. The receiver comprising a zero IF PLL jamming signal receiver having a synchronous demodulator and a phase detector, signal inputs thereof being coupled to said input means and carrier inputs coupled to in-phase and phase quadrature oscillator outputs, respectively, of a local voltage controlled oscillator (VCO), said VCO receiving a tuning control signal for tuning the zero IF PLL jamming signal receiver at the carrier frequency of the jamming signal. The VCO is included in a phase locked loop (PLL) comprising subsequent to the VCO, said phase detector and a loop filter. The replica jamming signal generator includes a tracking modulator with a baseband signal input coupled to an output of said synchronous demodulator and a carrier input coupled to the in-phase oscillator output of the VCO, an output of said modulator being negatively feedback to the input of the receiver. | 11-11-2010 |
20140141737 | ANTI-JAMMING SYSTEM - An anti-jamming system includes a tunable negative jamming signal feedback loop for feedback suppression of a received jamming signal. The system includes a zero IF phase locked loop (PLL) jamming signal receiver having a synchronous demodulator and a phase detector. A VCO is included in the PLL, as well as a phase detector and a loop filter. A replica jamming signal generator includes a tracking modulator with a baseband signal input coupled to an output of a synchronous demodulator in the receiver and a carrier input provided by the VCO. An output of the tracking modulator is negatively fed back to the input of the receiver to suppress the jamming signal in the received input. | 05-22-2014 |