Adaptation PLL bandwidth adjustment of jammer detection based in the FM receiver

摘要

By using a phase-locked loop (PLL), frequency synthesizer of the FM receiver generates a local oscillator (LO) signal. LO signal is provided to the mixer. Furthermore, FM receiver includes a jammer detection functionality. If the jammer is not detected, it is set to have a relatively high value, thereby, the loop bandwidth of the PLL, to promote the reduction of in-band residual FM. If a jammer is detected, it is set to have a relatively low value, whereby the loop bandwidth of the PLL, to promote the reduction of the band SSB phase noise. By adaptively change the loop bandwidth jammer depending on whether it is detected and, at the same time meet the band SSB phase noise requirements and band residual FM, alleviate the performance requirements for the sub-circuit within the PLL can be. By the VCO of the PLL is to be able to generate more phase noise due to changes in the adaptive loop bandwidth, it is possible to reduce the VCO power consumption. [Selection Figure 8