摘要:
A complex filter includes an I channel having a first I channel output and a second I channel output and a Q channel having a first Q channel output and a second Q channel output. The second I channel output is input to the Q channel through a first passive network and wherein the second Q channel output is input to the I channel through a second passive network.
摘要:
A communications system comprises a local oscillator configured to generate a local oscillator output and a signal processing component coupled to the local oscillator. The signal processing component is configured to receive a clock signal and the clock signal is derived from the local oscillator output. A method of demodulating an input signal comprises deriving a conversion signal from a local oscillator output, deriving a clock signal from the local oscillator output, mixing the input signal with the conversion signal to generate an intermediate frequency signal, and processing the intermediate frequency signal using a signal processing component driven by the clock signal. A method of modulating an input signal comprise deriving a conversion signal from a local oscillator output, deriving a clock signal from the local oscillator output, processing the input signal using a signal processing component driven by the clock signal to generate an intermediate frequency signal and mixing the intermediate frequency signal with the conversion signal to generate a modulated signal.
摘要:
A technique is disclosed for providing a charge pump circuit for phase locked loop (PLL) to reduce mismatch of up/down currents and feed-through of up/down currents to voltage output. Elimination of feed-through of the input signal may be achieved by using differential switches (M1 and M2, and M3 and M4) based on DC reference voltage in the charge pump and also eliminate the mismatch of up/down currents in a wide voltage output range by applying a new replica biasing using feedback.
摘要:
A multistandard RF transceiver is disclosed that may optionally include selectable mixers; selectable amplifiers; a configurable analog filter; and a configurable analog to digital converter. The multistandard RF transceiver may also include a data interface for sending data to a host controller and a control interface for receiving configuration commands from the host controller. The configuration commands identify a wireless standard that is to be implemented by the RF receiver. An RF processor processes an RF signal wherein the processed RF signal is output to the host controller on the data interface.
摘要:
A phase synchronous multiple LC tank oscillator is described. A plurality of oscillator stages are configured to oscillate synchronously. The phase of each of the plurality of oscillator stages is substantially the same and the plurality of oscillators are inductively coupled.
摘要:
A technique is disclosed for providing a charge pump circuit for phase locked loop (PLL) to reduce mismatch of up/down currents and feed-through of up/down currents to voltage output. Elimination of feed-through of the input signal may be achieved by using differential switches (M1 and M2, and M3 and M4) based on DC reference voltage in the charge pump and also eliminate the mismatch of up/down currents in a wide voltage output range by applying a new replica biasing using feedback.
摘要:
A precharge circuit that initializes an electronic filter to a middle voltage level of an operational voltage includes a filter isolation device, a filter communication device, and an initializing device. The filter isolation device isolates the electronic filter from electronic circuits connected to an input and an output of the electronic filter to segregate the electronic filter from the electronic circuits connected to the input and the output of the electronic filter during a precharge time. The filter communication device allows communication between the precharge circuit and the electronic filter for initializing the charge state during the precharge time. The initializing device provides an initializing signal to the charge state of the electronic filter during the precharge time. The precharge circuit further has a biasing device in communication with the initializing device to provide a mid level control signal providing a reference level of the charge state.
摘要:
A system and method are disclosed for providing a DLL with false lock protector to avoid false lock and ensure accurate lock. The false lock protector operates when the initial delay time between signals from an input reference clock and an output clock exceeds the lock range during operation of the DLL. The DLL with false lock protector includes a reference clock, a delay line composed of several delay cells connected in series, a phase detector, comparator for comparing phases of signals from the reference and output clocks, a determinator and a controller for controlling the delay of the delay line.
摘要:
A system and method are disclosed for providing a DLL with false lock protector to avoid false lock and ensure accurate lock. The false lock protector operates when the initial delay time between signals from an input reference clock and an output clock exceeds the lock range during operation of the DLL. The DLL with false lock protector includes a reference clock, a delay line composed of several delay cells connected in series, a phase detector, comparator for comparing phases of signals from the reference and output clocks, a determinator and a controller for controlling the delay of the delay line.
摘要:
A quadrature signal generator includes a polyphase filter where four resistive elements and four variable capacitive elements are connected alternately in series to form a loop; and a phase corrector that variably controls the capacitance of the variable capacitive elements.