Second-order filter with notch for use in receivers to effectively suppress the transmitter blockers

A mobile handset, comprising:

• a processor;
• a memory;
• a transceiver configured to send and receive a wireless communication signal;
• a differential reception path having a first differential branch and a second differential branch configured to conduct a differential input signal having a transmitter blocker;
• a transimpedance amplifier comprising:
• a first-order active low-pass filter configured to receive the differential input signal at a first differential input node in the first differential branch and a second differential input node in the second differential branch, and to filter the differential input signal;
• a tunable, passive notch filter configured to attenuate the differential input signal within a stop band frequency corresponding to a frequency of the transmitter blocker;
• a first feedback path extending from the second differential branch at a first output node of the transimpedance amplifier to the first differential input node, wherein the first feedback path is configured to provide a first negative feedback signal to the first differential branch;
• and
• a second feedback path extending from the first differential branch at a second output node of the transimpedance amplifier to the second differential input node, wherein the second feedback path is configured to provide a second negative feedback signal to the second differential branch.

A method for suppressing a transmitter blocker within a reception path, comprising:

• operating transceiver front end to receive an input signal having a transmitter blocker at an RF antenna;
• operating a first-order active filter to receive the input signal at a first differential branch and a second differential branch of the reception path and filter the received input signal;
• operating a notch filter element to attenuate the received input signal within a stop band frequency corresponding to a frequency of the transmitter blocker;
• providing a first negative feedback signal to the first differential branch via a first feedback path extending from an output node of the second differential branch;
• and
• providing a second negative feedback signal to the to the second differential branch via a second feedback path extending from an output node of the first differential branch.