Patent ID: 8588721

Claim:
A dual mode radio receiver circuit, comprising: a low noise amplifier (LNA) amplifying RF signals input to the LNA; an I/Q quadrature mixer having first and second in-phase (I) outputs, first and second quadrature (Q) outputs, and an RF input, the RF input accepting RF signal output from the low noise amplifier; a dual mode filter unit having: first, second, third, and fourth DCCFs (Digitally Controlled Current Followers), the first and second DCCFs accepting the first and second I outputs, respectively from the I/Q quadrature mixer, and the third and fourth DCCFs accepting the first and second Q outputs, respectively from the I/Q quadrature mixer; first, second, third and fourth CDNs (Current-Division Networks) configured for controlling the first, second third, and fourth DCCFs, respectively; fifth, sixth, seventh, and eighth DCCFs, the fifth, sixth, seventh, and eighth DCCFs being cross-couple connected to the first, second, third, and fourth DCCFs; fifth, sixth, seventh and eighth CDNs configured for controlling the fifth, sixth, seventh, and eighth DCCFs, respectively, each of the CDNs having a mode control input responsive to a mode control signal, α, the CDNs changing frequency passband channel characteristics exhibited by the dual mode filter unit responsive to the α control signal, thereby switching the dual mode filter unit between first and second modes of the dual mode filter unit; and a dual-mode filter unit output; a demodulator operably connected to the dual mode filter unit output when the dual mode filter unit is in the first mode; and an analog-to-digital converter (ADC) operably connected to the dual mode filter unit output when the dual mode filter unit is in the second mode.