Various embodiments of the invention relate to a high performance analog bandpass filter (BPF) with improved performance in suppressing parasitic passband. The BPF comprises a first loss-pass filter (LPF) coupled to a first RF port, a second LPF coupled to a second RF port, and at least one high-pass module coupled in series between the first LPF and the second LPF for band-pass tuning. A resonant circuit is composed by a shunt capacitor from the LPF, a shunt inductor from the high-pass module and a series inductor from the LPF coupled in between. Such layout empowers the LPFs triple functions: to function as a low-pass filter, to participate in resonant circuit for center frequency tuning of the BPF, and to suppress parasitic resonance. Such a triple-function of the LPFs gives the BPF an improvement in a compact but effective topology.

A low-noise amplifier in a receiver supporting a beam forming function may selectively change a phase shift for beam steering. The low-noise amplifier may include first and second transistors and a variable capacitance circuit connected to a gate of the second transistor. The variable capacitance circuit may selectively change capacitance thereof based on a capacitance control signal applied thereto according to beam-forming information, where the changed capacitance correspondingly causes a phase change in an output signal of the low-noise amplifier. A similar scheme may be employed for amplifiers in transmit signal paths to steer a transmit beam.

A low-noise amplifier in a receiver supporting a beam forming function may selectively change a phase shift for beam steering. The low-noise amplifier may include first and second transistors and a variable capacitance circuit connected to a gate of the second transistor. The variable capacitance circuit may selectively change capacitance thereof based on a capacitance control signal applied thereto according to beam-forming information, where the changed capacitance correspondingly causes a phase change in an output signal of the low-noise amplifier. A similar scheme may be employed for amplifiers in transmit signal paths to steer a transmit beam.

A distributor distributes an input signal to a first transmission line and a second transmission line. A high-pass filter, a first linearizer, and a first phase shifter disposed on the first transmission line adjust the phase and amplitude of an intermodulation distortion in a low-frequency range. A low-pass filter, a second linearizer, and a second phase shifter disposed on the second transmission line adjust the phase and amplitude of an intermodulation distortion in a high-frequency range. A synthesizer synthesizes the signal from the first transmission line and the signal from the second transmission line.

Apparatus and associated methods relate to a low-noise wideband active phase shifter. The low-noise wideband active phase shifter includes first and second transconductance cells, a fixed LC series network and a tunable LC series network configured to form an all-pass lattice network. The first and second transconductance cells, each include a transistor, a feedback network, and a transistor biasing network. The transistor has an input terminal and an output terminal. The negative feedback network electrically couples the input and output terminals of the transistor. The biasing network provides input and output biasing of the transistor. The fixed LC series network connects between the first and the second transconductance cells. The tunable LC series network connects between the first and the second transconductance cells.

Apparatus and associated methods relate to a low-noise wideband active phase shifter. The low-noise wideband active phase shifter includes first and second transconductance cells, a fixed LC series network and a tunable LC series network configured to form an all-pass lattice network. The first and second transconductance cells, each include a transistor, a feedback network, and a transistor biasing network. The transistor has an input terminal and an output terminal. The negative feedback network electrically couples the input and output terminals of the transistor. The biasing network provides input and output biasing of the transistor. The fixed LC series network connects between the first and the second transconductance cells. The tunable LC series network connects between the first and the second transconductance cells.

According to an aspect of present disclosure, a phase shifter for providing a desired phase shift to a very high frequency signal fabricated as part of the an integrated circuit comprises a first coil segment and a second coil segment together forming an inductor of first inductance value, a first capacitor of first capacitance value electrically connected parallel the inductor, a second capacitor of second capacitance value electrically connected between the first coil segment and the second coil segment and a resistor of a first resistance value electrically connected parallel to the second capacitor, in that, the inductor, first capacitor, second capacitor and the resistor together operative as a phase shifter such that when a input signal of a first frequency is presented across the first capacitor, the output signal across the resistor is phase shifted version of the input signal shifted in phase by a first angle.

According to an aspect of present disclosure, a phase shifter for providing a desired phase shift to a very high frequency signal fabricated as part of the an integrated circuit comprises a first coil segment and a second coil segment together forming an inductor of first inductance value, a first capacitor of first capacitance value electrically connected parallel the inductor, a second capacitor of second capacitance value electrically connected between the first coil segment and the second coil segment and a resistor of a first resistance value electrically connected parallel to the second capacitor, in that, the inductor, first capacitor, second capacitor and the resistor together operative as a phase shifter such that when a input signal of a first frequency is presented across the first capacitor, the output signal across the resistor is phase shifted version of the input signal shifted in phase by a first angle.

A transformer-type phase shifter or a phase-shift circuit includes a first coil and a second coil that is magnetically coupled to the first coil with a coupling coefficient of less than 1, a transformer including a parallel inductance component and a series inductance component, and an impedance adjustment circuit including a reactance element that performs impedance adjustment for the transformer, thus being advantageous in reducing the size, loss, and frequency dependency of the phase-shift amount.

A transformer-type phase shifter or a phase-shift circuit includes a first coil and a second coil that is magnetically coupled to the first coil with a coupling coefficient of less than 1, a transformer including a parallel inductance component and a series inductance component, and an impedance adjustment circuit including a reactance element that performs impedance adjustment for the transformer, thus being advantageous in reducing the size, loss, and frequency dependency of the phase-shift amount.