Abstract: Systems, devices, and methods are provided for mixed-mode signal processing that achieves unprecedented levels of out-of-band and in-band interference suppression. Embodiments of the present disclosure mitigate the effects of blockers and jammers, which have surfaced as issues in emerging cognitive radio systems as those networks struggle to co-exist with licensed and unlicensed users.

Abstract: An apparatus and methods for timing mismatch in a power amplifier includes a segmented PA with two-path timing mismatch calibration to improve ACLR performance over different signal transitions, process, voltage and temperature (PVT) variations and device aging; a fast and efficient algorithm for measuring and calibrating the delay of two paths (signal path and control path); a signal magnitude variation detection circuit, such as flash ADC, with improved comparator's performance for RF signal processing and minimum delay. A method for choosing the threshold voltage of the magnitude variation detection circuit, according to status of the signals and orthogonal frequency-division multiplexing (OFDM) related standards; other critical blocks.

Abstract: An amplifier for signal amplification, the amplifier comprising: a signal input arrangement; a signal output arrangement; a first transistor; a second transistor; and a third transistor, wherein: the first, second and third transistors are coupled to one another to form a transconductance cell, the transconductance cell is coupled to the signal input arrangement and the signal output arrangement, and the transconductance cell is operable to receive a first signal from the signal input arrangement, amplify the first signal and output an amplified first signal to the signal output arrangement. There is also disclosed a receiver incorporating the amplifier and methods of operating the amplifier.

Abstract: A silicon based (e.g., SiGe, CMOS, or BiCMOS) transmitter includes an algorithm that strategically segment and pre-distort the input signal according to its power; a reconfigurable power amplifier (PA) having a plurality of PA sections, wherein the plurality of PA sections comprise discrete weighted transistor arrays that are digitally turned OFF or ON according to a magnitude of an input signal; an impedance matching network equipped with a common-mode feedback (CMFB) mechanism configured to reduce common-mode glitches at an output of the PA due to ON/OFF manipulations of the PA segments; and a 1:N transformer, which comprises a capacitive matching engine and a power detector, disposed between the impedance matching network and the reconfigurable linear PA.

Abstract: Systems, devices, and methods are provided for mixed-mode signal processing that achieves unprecedented levels of out-of-band and in-band interference suppression. Embodiments of the present disclosure mitigate the effects of blockers and jammers, which have surfaced as issues in emerging cognitive radio systems as those networks struggle to co-exist with licensed and unlicensed users.

Abstract: A variable bandwidth filter is described herein, wherein a bandwidth of a passband of the variable bandwidth filter is dynamically tunable. The variable bandwidth tuner is implemented on a CMOS chip, and acts to filter analog signals. The variable bandwidth filter comprises a plurality of finite impulse response (FIR) filters, wherein each FIR filter comprises a plurality of tunable transconductors. The tunable transconductors are tunable in their gain.

Abstract: An amplifier for signal amplification, the amplifier comprising: a signal input arrangement; a signal output arrangement; a first transistor (Q1); a second transistor (Q2); and a third transistor (Q3), wherein: the first (Q1), second (Q2) and third (Q3) transistors are coupled to one another to form a transconductance cell, the transconductance cell is coupled to the signal input arrangement and the signal output arrangement, and the transconductance cell is operable to receive a first signal from the signal input arrangement, amplify the first signal and output an amplified first signal to the signal output arrangement. There is also disclosed a receiver incorporating the amplifier and methods of operating the amplifier.

Abstract: Described herein is a power-efficient Gm-C filter, wherein the Gm-C filter includes several operational transconductance amplifiers (OTAs). In an example, at least two of the OTAs share a common bias current. Further, output of one of the OTAs is used to bias another one of the OTAs. Also described herein is a power-efficient clock generator circuit that is configured to output non-overlapping clock signals. The clock generator circuit includes a ring oscillator circuit, which includes several inverter stages. The clock generator circuit is well-suited for controlling operation of switches.

Abstract: Described herein are various technologies relating to processing a coherent signal. A receiver is configured to receive an analog signal, and process the analog signal to generate an input analog signal. The input analog signal has been modulated according to a suitable modulation sequence. A coherent signal sampler coherently samples the modulation sequence, and the result of such sampling is in turn used to demodulate the input analog signal. The resultant signal is then passed to a sigma delta modulator, where it is converted to digital form.

Abstract: A continuous-time delta-sigma analog-to-digital converter (ADC) is disclosed. The ADC includes a loop filter, a loop quantizer, and a clock-jitter tolerant digital-to-analog converter (DAC). The clock-jitter tolerant DAC includes a dual switched-current (SI) DAC, a switched-capacitor (SC) DAC, an adder, and a switched-capacitor-resistor (SCR) injection circuit. The dual SI DAC provides two identical analog signals from the feedback digital signal of a loop quantizer within the ADC. The SC DAC provides an error-free reference signal from the feedback digital signal. The adder subtracts one of the two analog signals from the error-free reference signal to obtain an inverted jitter-induced error signal. The SCR injection circuit then injects the inverted jitter-induced error signal, delayed by one clock-cycle, in the form of a half-delay return-to-zero exponentially decaying waveform into the loop filter.

Abstract: A continuous-time delta-sigma analog-to-digital converter (ADC) is disclosed. The ADC includes a loop filter, a loop quantizer, and a clock-jitter tolerant digital-to-analog converter (DAC). The clock-jitter tolerant DAC includes a dual switched-current (SI) DAC, a switched-capacitor (SC) DAC, an adder, and a switched-capacitor-resistor (SCR) injection circuit. The dual SI DAC provides two identical analog signals from the feedback digital signal of a loop quantizer within the ADC. The SC DAC provides an error-free reference signal from the feedback digital signal. The adder subtracts one of the two analog signals from the error-free reference signal to obtain an inverted jitter-induced error signal. The SCR injection circuit then injects the inverted jitter-induced error signal, delayed by one clock-cycle, in the form of a half-delay return-to-zero exponentially decaying waveform into the loop filter.