Qualcomm Incorporated

Apple Inc.

Milad Darvishi

Hajir Hedayati

Jeremy Darren Dunworth

Faramarz Sabouri

Li-chung Chang

Georgios Yorgos Palaskas

Haowei Jiang

Li-Chung Chang

An electronic device may include wireless circuitry having digital-to-analog converters, filters, mixers, and current buffers disposed between the filters and the mixers. The current buffers may provide proper resistance termination for the filters. The current buffers may include current mirrors formed from diode-connected n-type transistors and diode-connected p-type transistors, which collectively provide a linear input resistance. The current mirrors may receive a high voltage from a voltage regulator having a replica current mirror and proportional-to-absolute-temperature current sources.

Electronic devices having complementary current mirror circuitry

An electronic device may include wireless circuitry having a radio-frequency mixer. The mixer may include a first pair of mixer transistors configured to receive an oscillating signal, a second pair of mixer transistors configured to receive the oscillating signal, and a bias circuit configured to receive the oscillating signal and to generate a corresponding output voltage for controlling an amount of current flowing through the first and second pairs of mixer transistors. The bias circuit can be configured as a replica envelope detection circuit. The bias circuit can include a pair of bias transistors coupled to a tail transistor that receives the output voltage of the replica envelope detection circuit.

Radio-frequency mixer with stabilized biasing

An electronic device may include wireless circuitry having an LC filter. The LC filter may include first and second series inductors coupled between the input and output of the LC filter. An input capacitor can be coupled at the input of the LC filter, and an output capacitor can be coupled at the output of the LC filter. Feedforward capacitors can be cross-coupled with the first and second series inductors to at least partially or fully cancel out any parasitic capacitance associated with the first and second series inductors to mitigate any undesired self-resonant effects associated with the series inductors.

Electronic devices with differential LC filters

Certain aspects of the present disclosure provide an N-path filter implemented using a generalized impedance converter (GIC) circuit. The GIC circuit is configured such that the N-path filter has a desired frequency response, which may include a wide passband with steeper rejection than a conventional N-path filter with only a single pole in each filter path. Certain aspects of the present disclosure provide an N-path filter having a frequency response with multiple concurrent passbands. In certain aspects, the N-path filter with multiple passbands is implemented using the GIC circuit. In other aspects, the N-path filter may include a bandpass response circuit where an inductance of the bandpass response circuit may be implemented using gyrators.

High rejection wideband bandpass N-path filter

Certain aspects of the present disclosure provide N-path filters with wider passbands and steeper rejection than conventional N-path filters with only a single pole in each filter path. These N-path filters also have a flatter passband with decreased passband droop. One example N-path filter generally includes a plurality of branches selectively connected with a common node, each branch of the N-path filter comprising a switch connected in series with an impedance comprising a common drain amplifier circuit. In certain aspects, the amplifier circuit may include a degeneration circuit for stability and/or a poly-phase feedback circuit to reduce in-band peaking.

N-path filters with flatter frequency response

A radio frequency (RF) receiver device may include a receive path including a first amplifier. The device also includes a first mixer coupled to an output of the first amplifier and to an input of a second amplifier. Further, the device may include an auxiliary path including a second mixer coupled between an output of the first mixer and an input of the first mixer.

Noise suppression in radio frequency receivers

An apparatus includes a low noise amplifier (LNA) having an input configured to receive a radio frequency signal. The apparatus also includes a notch filter coupled to an input of the LNA. The notch filter is configured to attenuate the radio frequency signal at a notch frequency.

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San Diego, CA, United States of America

Milad Darvishi