Signal reception front-end circuit, signal reception circuit, and communication apparatus comprising the same

A signal reception circuit for use in a communication apparatus, comprising:

• a gain switch circuit of regulating a level of a received signal;
• and
• a signal reception front-end circuit connected to an output of the gain switch circuit,
• wherein the signal reception front-end circuit comprises:
• a folded load downconverter circuit comprising a mixer circuit, a current mirror circuit and a load circuit, wherein the current mirror circuit folds an output of the mixer circuit, and the load circuit is connected to a folded output of the current mirror circuit;
• a detection circuit of detecting an input signal or an output signal of the folded load downconverter circuit;
• a smoothing circuit of smoothing an output signal of the detection circuit;
• a reference comparison circuit of comparing an output signal of the smoothing circuit with a predetermined reference voltage;
• and
• a bias control circuit of controlling a bias of the folded load downconverter circuit, depending on a result of comparison by the reference comparison circuit.

A communication apparatus for performing wireless communication, comprising:

• an antenna of transmitting/receiving a radio wave;
• an antenna-sharing circuit connected to the antenna;
• a transmission circuit connected to the antenna-sharing circuit;
• and
• a signal reception circuit connected to the antenna-sharing circuit,
• wherein the signal reception circuit comprises:
• a gain switch circuit of regulating a level of a received signal output from the antenna-sharing circuit;
• and
• a signal reception front-end circuit connected to an output of the gain switch circuit,
• wherein the signal reception front-end circuit comprises:
• a folded load downconverter circuit comprising a mixer circuit, a current mirror circuit and a load circuit, wherein the current mirror circuit folds an output of the mixer circuit, and the load circuit is connected to a folded output of the current mirror circuit;
• a detection circuit of detecting an input signal or an output signal of the folded load downconverter circuit;
• a smoothing circuit of smoothing an output signal of the detection circuit;
• a reference comparison circuit of comparing an output signal of the smoothing circuit with a predetermined reference voltage;
• and
• a bias control circuit of controlling a bias of the folded load downconverter circuit, depending on a result of comparison by the reference comparison circuit.