Abstract:
Disclosed herein is an optical filter configured for wavelength division and multiplexing capable of transmitting and receiving signals. The optical filter includes an optical waveguide configured to receive at an input multiple signals with different wavelengths. The optical filter includes a plurality of channels coupled at different locations along a length of the optical waveguide. Each of the plurality of channels is configured to transmit a respective one of the multiple signals. A number of ring filter stages in a first channel of the plurality of channels that is closer to the input of the optical waveguide is greater than a second channel in the plurality of channels further away from the input of the optical waveguide.
Abstract:
Transformer based voltage controlled oscillator circuitry for phase-locked loop circuitry includes upper band circuitry and lower band circuitry. The upper band circuitry operates in a first frequency range and includes a first capacitor array having a variable capacitance. The lower band circuitry operates in a second frequency range and includes a second capacitor array having a variable capacitance. The first frequency range higher than the second frequency range. In a first operating mode, the first capacitor array has a first capacitance value and the second capacitor array has a second capacitance value. In a second operating mode, the second capacitor array has a third capacitance value different than the second capacitance value.
Abstract:
An apparatus for reducing or removing a direct current (DC) offset voltage from one or more analog signals is disclosed. An analog signal may be received by an integrator. The integrator may integrate the analog signal to determine a DC offset error signal. The apparatus may integrate, invert, and amplify the DC offset error signal to provide an analog correction signal. The analog correction signal may be inverted and subtracted from the analog signal. In some implementations, the apparatus may include multiple, independent circuits to reduce or remove DC offset voltages from differential signals.
Abstract:
Apparatus and associated methods relate to automatically generating a data structure representation of an on-chip inductive-capacitive (LC) tank circuit by determining parasitic inductances in each of the segments of conductive paths that connect a main inductor to one or more selectable VCO components such as capacitors and varactors, for example. In an illustrative example, one or more of the selectable VCO components may be arranged, when selected, to form a parallel resonant LC tank with the main inductor. A method may include defining nodes ai terminating each of the segments along the conductive paths between the main inductor terminals and a drive circuit. By modelling the paths as multi-port inductors and transformers, resonant frequency of the VCO may be more accurately predicted by simulation.
Abstract:
Methods and apparatus are described for a differential active inductor load for inductive peaking in which cross-coupled capacitive elements are used to cancel out, or at least reduce, the limiting effect of the gate-to-drain capacitance (Cgd) of transistors in the active inductor load. The cross-coupled capacitive elements extend the range over which the active inductor load behaves inductively and increase the quality factor (Q) of each active inductor. Therefore, the achievable inductive peaking of the load is significantly increased, which leads to providing larger signal swing across the load for a given power or, alternatively, lower power for a given signal swing.
Abstract:
An example clock generator circuit includes a fractional reference generator configured to generate a reference clock in response to a base reference clock and a phase error signal, the reference clock having a frequency that is a rational multiple of a frequency of the base reference clock. The clock generator circuit includes a digitally controlled delay line (DCDL) that delays the reference clock based on a first control code, and a pulse generator configured to generate pulses based on the delayed reference clock. The clock generator circuit includes a digitally controlled oscillator (DCO) configured to generate an output clock based on a second control code, the DCO including an injection input coupled to the pulse generator to receive the pulses. The clock generator circuit includes a phase detector configured to compare the output clock and the reference clock and generate the phase error signal, and a control circuit configured to generate the first and second control codes based on the phase error signal.
Abstract:
An apparatus, and method therefor, relate generally to broadband IQ generation. In this apparatus, related generally to broadband in-phase and quadrature phase (“IQ”) generation, a divider circuit and a polyphase filter circuit are configured for receiving an oscillator output. The polyphase filter circuit is configured for polyphase filtering the oscillator output into a first quadrature output. The divider circuit is configured for dividing the oscillator output into a second quadrature output. A multiplexer circuit is coupled to the divider circuit and the polyphase filter circuit and configured for selecting either the first quadrature output or the second quadrature output as an IQ output based on a bandwidth of the oscillator output.
Abstract:
A circuit for generating a divided clock signal with a configurable phase offset comprises a first latch circuit adapted to receive a clock signal to be divided; a second latch coupled to an output of the first latch circuit and generating a divided output clock signal; and an initialization circuit coupled to the first latch circuit and the second latch circuit, the initialization circuit coupled to receive an initialization signal. The initialization signal determines a phase offset between the divided output clock signal and the clock signal to be divided. A method of generating a divided clock signal is also described.
Abstract:
An input/output circuit implemented in an integrated circuit is described. The input/output circuit comprises an input/output pad and a voltage control circuit coupled to the input/output pad. The voltage control circuit sets a voltage at the input/output pad at a first voltage when the input/output pad is implemented as an input pad and at a second voltage when the input/output pad is implemented as an output pad. Methods of implementing input/output circuits in an integrated circuit are also described.
Abstract:
A transceiver circuit is disclosed. The transceiver circuit includes a transmitter driver circuit configured to drive a transmit antenna. The transceiver circuit also includes a receiver circuit configured to generate digital signals based on received signals. The transceiver circuit also includes a loopback data path circuit electrically connected to the transmitter driver circuit and to the receiver circuit, where the loopback data path circuit is configured to conditionally provide signals from the transmitter driver circuit to the receiver circuit according to one or more control signals. The transceiver circuit also includes a controller configured to generate the control signals.