Reconfigurable local oscillator for optimal noise performance in a multi-standard transceiver

摘要

A transceiver for multi-standard operation (usable, for example, to communicate signals both of a first wireless communication standard and of a second wireless communication standard) has a mixer that receives a local oscillator signal generated by a local oscillator. A PLL of the local oscillator involves a VCO, a digitally programmable analog loop filter, a digitally programmable VCO supply voltage circuit, and a digitally programmable VCO varactor bias control circuit. In one aspect, the bandwidth of the analog loop filter is adjusted depending on the communication standard of the signal being communicated. In other aspects, the VCO supply voltage circuit and/or the varactor bias control circuit are configured in different ways to optimize PLL performance depending on the communication standard of the signal being communicated.

主权项

1. An apparatus comprising:
transceiver circuitry usable to communicate a first wireless communication signal and a second wireless communication signal, wherein the first wireless communication signal complies with a first wireless communication standard, and wherein the second wireless communication signal complies with a second wireless communication standard; and a local oscillator that generates a local oscillator signal that is supplied to the transceiver circuitry, wherein the local oscillator comprises a Phase-Locked Loop (PLL) that includes a digitally programmable analog loop filter, and a digitally programmable Voltage-Controlled Oscillator (VCO) comprising a VCO and a digitally programmable VCO supply voltage circuit that draws power from a first supply voltage conductor and supplies a first regulated voltage to the VCO when the transceiver circuitry is communicating the first wireless communication signal, wherein the digitally programmable VCO supply voltage circuit draws power from a second supply voltage conductor and supplies a second regulated voltage to the VCO when the transceiver circuitry is communicating the second wireless communication signal.