A digital control circuitry for a MEMS gyroscope is provided. The digital control circuitry comprises a digital primary loop circuitry configured to process a digitized primary signal, a digital secondary loop circuitry configured to process a digitized secondary signal and a digital phase shifting filter circuitry configured to generate two phase shifted demodulation signals from the digitized primary signal. The digital secondary loop is configured to demodulate the digitized secondary signal using the two phase shifted demodulation signals.

An apparatus and a method. The apparatus includes a first low pass filter (LPF), a second LPF, a first analog-to-digital converter (ADC), a second ADC, a first discrete Fourier transform (DFT) unit, a second DFT unit, a second order intermodulation (IM2) tone amplitude measurement unit, and a calibration logic unit configured to simultaneously determine an in-phase mixer (I-mixer) digital-to-analog (DAC) code and a quadrature-phase mixer (Q-mixer) DAC code.

Differential mixer circuitry comprising: first and second input-voltage nodes and first and second input-current nodes; a passive network of impedances connected between the first and second input-voltage nodes and the first and second input-current nodes, and configured to convert first and second input-voltage signals received at the first and second input-voltage nodes, respectively, into first and second input-current signals provided at the first and second input-current nodes, respectively, the first and second input-voltage signals defining a differential input-voltage signal having an input frequency, and the first and second input-current signals defining a differential input-current signal; and a mixing stage configured to mix the differential input-current signal with at least one mixing signal having a corresponding mixing frequency and output a differential output signal having an output frequency dependent on the input frequency and each mixing frequency.

Differential mixer circuitry comprising: first and second input-voltage nodes and first and second input-current nodes; a passive network of impedances connected between the first and second input-voltage nodes and the first and second input-current nodes, and configured to convert first and second input-voltage signals received at the first and second input-voltage nodes, respectively, into first and second input-current signals provided at the first and second input-current nodes, respectively, the first and second input-voltage signals defining a differential input-voltage signal having an input frequency, and the first and second input-current signals defining a differential input-current signal; and a mixing stage configured to mix the differential input-current signal with at least one mixing signal having a corresponding mixing frequency and output a differential output signal having an output frequency dependent on the input frequency and each mixing frequency.

The disclosure relates to technology for a receiver having a receive signal path including a mixer, a differential fixed gain or variable gain amplifier, and a differential filter. The mixer is configured to receive an RF signal, receive an oscillator signal, and output a differential down converted signal at one of a baseband or intermediate frequency (IF). The amplifier is downstream of the mixer and configured to receive the differential down converted signal from the mixer, apply a gain thereto, and output an amplified differential signal. The filter is downstream of the amplifier and configured filter the amplified differential signal received from the amplifier, and output a filtered differential signal. By locating the differential filter downstream of the differential amplifier within the receive signal path, distortion caused by the mixer is mitigated compared to if the filter were located upstream of the filter.

The disclosure relates to technology for a receiver having a receive signal path including a mixer, a differential fixed gain or variable gain amplifier, and a differential filter. The mixer is configured to receive an RF signal, receive an oscillator signal, and output a differential down converted signal at one of a baseband or intermediate frequency (IF). The amplifier is downstream of the mixer and configured to receive the differential down converted signal from the mixer, apply a gain thereto, and output an amplified differential signal. The filter is downstream of the amplifier and configured filter the amplified differential signal received from the amplifier, and output a filtered differential signal. By locating the differential filter downstream of the differential amplifier within the receive signal path, distortion caused by the mixer is mitigated compared to if the filter were located upstream of the filter.

A communication unit (300, 400, 500) is described that includes at least one antenna (302, 402, 502); a plurality of radio frequency (RF) circuits (304, 310, 404, 410) respectively coupled to at least one antenna (302, 402, 502); at least one sigma-delta modulator (316, 416, 616, 816) comprising a number of stages, each stage comprising at least one signal-feedforward coefficient (603, 604, 605), a filter and a feedback gain element, the at least one sigma-delta modulator (316, 416, 616, 816) coupled to the plurality of RF circuits (304, 310, 404, 410) and configured to perform sigma-delta modulation; and a controller (340, 440, 640, 840) operably coupled to the at least one sigma-delta modulator (316, 416, 616, 816). The at least one sigma-delta modulator (316, 416, 616, 816) comprises an input (315, 415, 602, 801, 802, 902) configured to receive multiple multi-phase input signals and the controller (340, 440, 640, 840) is configured to adjust the at least one signal-feedforward coefficient (603, 604, 605) of the at least one sigma-delta modulator (316, 416, 616, 816) when combining the multiple multi-phase input signals.

A circuit for demodulating an input signal is described. The circuit may be configured to demodulate signals modulated with amplitude-based modulation schemes, such as amplitude shift keying (ASK). The demodulator may comprise a clock extractor configured to generate a clock signal in response to receiving an amplitude-modulated input signal, a phase shifter configured to generate a sampling signal by phase-shifting the clock signal by approximately /2, and a sampler configured to sample the input signal in correspondence to one or more edges (such as one or more falling edges) of the sampling signal. In this way, the amplitude-modulated input signal may be sampled at its peak, or at least near its peak, thus ensuring high signal fidelity.

A digital control circuitry for a MEMS gyroscope is provided. The digital control circuitry comprises a digital primary loop circuitry configured to process a digitized primary signal, a digital secondary loop circuitry configured to process a digitized secondary signal and a digital phase shifting filter circuitry configured to generate two phase shifted demodulation signals from the digitized primary signal. The digital secondary loop is configured to demodulate the digitized secondary signal using the two phase shifted demodulation signals.

A communication unit (300, 400, 500) is described that includes at least one antenna (302, 402, 502); a plurality of radio frequency (RF) circuits (304, 310, 404, 410) respectively coupled to at least one antenna (302, 402, 502); at least one sigma-delta modulator (316, 416, 616, 816) comprising a number of stages, each stage comprising at least one signal-feedforward coefficient (603, 604, 605), a filter and a feedback gain element, the at least one sigma-delta modulator (316, 416, 616, 816) coupled to the plurality of RF circuits (304, 310, 404, 410) and configured to perform sigma-delta modulation; and a controller (340, 440, 640, 840) operably coupled to the at least one sigma-delta modulator (316, 416, 616, 816). The at least one sigma-delta modulator (316, 416, 616, 816) comprises an input (315, 415, 602, 801, 802, 902) configured to receive multiple multi-phase input signals and the controller (340, 440, 640, 840) is configured to adjust the at least one signal-feedforward coefficient (603, 604, 605) of the at least one sigma-delta modulator (316, 416, 616, 816) when combining the multiple multi-phase input signals.