Configurable filter for subharmonic blockers in multiband wireless receivers

A multiband radio receiver or transceiver, comprising:

• a low-noise amplifier with a differential input comprising an inverting input and a non-inverting input;
• a differential tunable radio frequency filter acting as a non-band-specific preselection filter of the multiband radio receiver or transceiver, the differential tunable radio frequency filter comprising:
• a pair of tunable radio frequency filters comprising a first tunable radio frequency filter for connecting to the non-inverting input of the differential low-noise amplifier and a second tunable radio frequency filter for connecting to the inverting input of the differential low-noise amplifier, wherein each of the at least one tunable radio frequency filter comprises:
• a first capacitor having a first terminal for connecting to at least one antenna of the multiband radio receiver or transceiver and a second terminal;
• a second capacitor connected, via a first terminal of the second capacitor, to the second terminal of the first capacitor and, via a second terminal of the second capacitor, to the differential input of the low-noise amplifier;
• and
• a series resonant circuit, connected between the second terminal of the first capacitor and the ground, comprising
• a first inductor and
• a tunable capacitor connected in series with first inductor and having a plurality of tuning capacitance values corresponding to operating frequency bands of the multiband radio receiver or transceiver, wherein the tunable capacitor is implemented in an integrated circuit, the series resonant circuit being configured to be resonant at a plurality of first subharmonics of frequencies of the operating frequency bands when the tunable capacitor is set to the plurality of tuning capacitance values, respectively, a first subharmonic of a given frequency being a frequency equal to said given frequency divided by two.