A radio frequency (RF) transmitter includes a set of input ports to receive baseband, a set of filter banks for each input port that includes a plurality of digital polyphase interpolation filters, and a set of oscillators banks, wherein each oscillator bank includes a plurality of polyphase Digital Direct Synthesizer (DDS) corresponding to the plurality of digital polyphase interpolation filters. The RF transmitter includes a set of mixer banks to mix corresponding sequences of samples of digital waveform, a parallel digital combiner to combine in-phase sequences of interpolated baseband phased samples, and a pulse encoder to modulate and encode the plurality of sequences of multiband upconverted samples. The RF transmitter converts a plurality of encoded multi-band signals into a RF bitstream and an E/O interface to convert the RF bitstream.

In some examples, a sigma-delta analog-to-digital converter (ADC), comprises a first set of switches configured to receive a first voltage signal; a second set of switches coupled to the first set of switches at a first node and a second node, the second set of switches configured to receive a second voltage signal; an integrator including a first input sampling capacitor coupled to the first node and a second input sampling capacitor coupled to the second node, wherein the integrator configured to generate a first output signal. The sigma-delta ADC further comprises a comparator coupled to the integrator and configured to generate a second output signal based on the first output signal; and a controller unit having a first counter, a second counter, and a processor, the controller unit coupled to the first and second sets of switches, the integrator, and the comparator.

A system may include a delta-sigma analog-to-digital converter and a digital compression circuit. The delta-sigma analog-to-digital converter may include a loop filter having a loop filter input configured to receive an input signal and generate an intermediate signal responsive to the input signal, a multi-bit quantizer configured to quantize the intermediate signal into an uncompressed digital output signal, and a feedback digital-to-analog converter having a feedback output configured to generate a feedback output signal responsive to the uncompressed digital output signal in order to combine the input signal and the feedback output signal at the loop filter input. The digital compression circuit may be configured to receive the uncompressed digital output signal and compress the uncompressed digital output signal into a compressed digital output signal having fewer quantization levels than that of the uncompressed digital output signal.

In some examples, a sigma-delta analog-to-digital converter (ADC), comprises a first set of switches configured to receive a first voltage signal; a second set of switches coupled to the first set of switches at a first node and a second node, the second set of switches configured to receive a second voltage signal; an integrator including a first input sampling capacitor coupled to the first node and a second input sampling capacitor coupled to the second node, wherein the integrator configured to generate a first output signal. The sigma-delta ADC further comprises a comparator coupled to the integrator and configured to generate a second output signal based on the first output signal; and a controller unit having a first counter, a second counter, and a processor, the controller unit coupled to the first and second sets of switches, the integrator, and the comparator.

Provided is a transmission system including: a signal processing apparatus 2 configured to transmit, via a signal cable 4, a delta-sigma modulated signal obtained by performing delta-sigma modulation on a transmission signal that is an RF signal; and a wireless apparatus 3 configured to transmit, via the signal cable 4, a reception signal that is an RF signal. The signal processing apparatus 2 transmits the delta-sigma modulated signal to the wireless apparatus 3, and the wireless apparatus 3 transmits the reception signal to the signal processing apparatus 2. In the delta-sigma modulated signal, quantization noise is suppressed at the frequency of the reception signal. The reception signal is transmitted to the signal processing apparatus 2 while the delta-sigma modulated signal is being transmitted to the wireless apparatus 3.

Disclosed herein is an apparatus for measuring a voltage. The apparatus includes a primary integrator circuit configured to operate as a first integral stage of a sigma-delta analog-to-digital converter circuit when switched by a first control signal from a controller, a secondary integrator circuit configured to operate as a second integral stage when switched by a second control signal from the controller, a comparator configured to compare final voltages modulated through the primary integrator circuit and the secondary integrator circuit, and a digital filter configured to delay an output of the comparator by a specified number of clocks according to a switching of the controller, pass the delayed output through a digital-to-analog converter (DAC) to feed the delayed output back to the primary and secondary integrator circuits, and receive the delayed output signal of the comparator as an input. An output of the digital filter becomes a final measured value.

An idle tone dispersion device outputs a frequency delta-sigma modulation signal obtained by using either one of a reference signal and a measured signal to perform frequency delta-sigma modulation of the other and dispersing an idle tone. The idle tone dispersion device includes n (n is any natural number equal to or larger than 2) frequency delta-sigma modulation sections and an adder configured to add up output signals of the n frequency delta-sigma modulation sections and output the frequency delta-sigma modulation signal. Each of the n frequency delta-sigma modulation sections uses either one of the reference signal and the measured signal to perform the frequency delta-sigma modulation of the other. At least one of the reference signal and the measured signal includes jitter including a frequency component higher than a frequency of an idle tone of an output signal of the frequency delta-sigma modulation section.

Provided is a transmission system including: a signal processing apparatus 2 configured to transmit, via a signal cable 4, a delta-sigma modulated signal obtained by performing delta-sigma modulation on a transmission signal that is an RF signal; and a wireless apparatus 3 configured to transmit, via the signal cable 4, a reception signal that is an RF signal. The signal processing apparatus 2 transmits the delta-sigma modulated signal to the wireless apparatus 3, and the wireless apparatus 3 transmits the reception signal to the signal processing apparatus 2. In the delta-sigma modulated signal, quantization noise is suppressed at the frequency of the reception signal. The reception signal is transmitted to the signal processing apparatus 2 while the delta-sigma modulated signal is being transmitted to the wireless apparatus 3.

In accordance with embodiments of the present disclosure, a processing system may include multiple selectable processing paths for processing an analog signal in order to reduce noise and increase dynamic range. Techniques are employed to transition between processing paths and calibrate operational parameters of the two paths in order to reduce or eliminate artifacts caused by switching between processing paths.

A digital sigma-delta modulator may be provided that includes: a multiplexer which receives N-bit input data from each of M number of input terminals and sequentially outputs; an adder which outputs carry out (CO) data and N-bit added data obtained by adding the N-bit input data and N-bit added data output in a previous cycle; a memory which divides the N-bit added data output from the adder into A-bit added data and (NA)-bit added data and stores the A-bit added data and the (NA)-bit added data; and a demultiplexer which receives the output carry out (CO) data and outputs to each of M number of output terminals.