Patent classifications
H03C2200/0058
Transmitter with quantization noise compensation
The invention discloses a transmitter comprising a pulse encoder for creating pulses from the amplitude of an input signal to the transmitter, a compensation signal generator for cancelling quantization noise caused by the pulse encoder, a mixer or I/Q modulator for mixing an output of the pulse encoder with the phase of an input signal to the transmitter, said output of the pulse encoder comprising the amplitude of the complex input signal plus the quantization noise caused by the pulse encoder, and an amplifier for creating an output signal from the transmitter. In the transmitter, a control signal (C.sub.A) for controlling a function of the amplifier comprises an output signal from the compensation signal generator, and an input signal to the amplifier comprises an output from the mixer having been modulated to a desired frequency.
Method and Apparatus to Detect LO Leakage and Image Rejection using a Single Transistor
Local oscillator (LO) leakage and Image are common and undesirable effects in typical transmitters. Typically, fairly complex hardware and algorithms are used to calibrate and reduce these impairments. A single transistor that draws essentially no dc current and occupies a very small area detects the LO leakage and Image signals. The single transistor operating as a square-law device is used to mix the signals at the input and output ports of a power amplifier. The mixed signal generated by the single transistor enables the simultaneous calibration of the LO leakage and Image Rejection.
Zero IF transmitter with decoupling between mixer and programmable gain stage
A system includes a Zero IF transmitter having a mixer and a programmable gain stage. The Zero IF transmitter also includes an intermediate stage between the mixer and the programmable gain stage, wherein the intermediate stage is configured to decouple the mixer and the programmable gain stage.
Transceiver carrier frequency tuning
In described examples, a method of operating a transceiver with a transmitter and a receiver includes generating a frequency reference. In the transmitter: A phase locked loop (PLL) generates a first voltage controlled oscillator (VCO) control voltage responsive to the frequency reference. A VCO in the transmitter generates a transmitter VCO signal responsive to the first VCO control voltage, and the PLL is locked to the transmitter VCO signal. In the receiver: A signal is received. A receiver VCO generates a receiver VCO signal responsive to the first or a second VCO control voltage. The receiver VCO signal is multiplied by the received signal to generate an I component, and by the received signal phase shifted by 90° to generate a Q component. The second VCO control signal is generated responsive to the I component and the Q component.
TRANSCEIVER CARRIER FREQUENCY TUNING
In described examples, a method of operating a transceiver with a transmitter and a receiver includes generating a frequency reference. In the transmitter: A phase locked loop (PLL) generates a first voltage controlled oscillator (VCO) control voltage responsive to the frequency reference. A VCO in the transmitter generates a transmitter VCO signal responsive to the first VCO control voltage, and the PLL is locked to the transmitter VCO signal. In the receiver: A signal is received. A receiver VCO generates a receiver VCO signal responsive to the first or a second VCO control voltage. The receiver VCO signal is multiplied by the received signal to generate an I component, and by the received signal phase shifted by 90° to generate a Q component. The second VCO control signal is generated responsive to the I component and the Q component.
Method and signal generator for producing a control signal for an acousto-optical element
A method for generating a control signal for an acousto-optical element includes generating a raw signal using at least one correction term by an IQ modulation from a target I component and a target Q component, and amplifying the raw signal to become the control signal. The target I component and/or the target Q component are corrected using the at least one correction term. The at least one correction term is obtained from an analysis of the control signal.
ZERO IF TRANSMITTER WITH DECOUPLING BETWEEN MIXER AND PROGRAMMABLE GAIN STAGE
A system includes a Zero IF transmitter having a mixer and a programmable gain stage. The Zero IF transmitter also includes an intermediate stage between the mixer and the programmable gain stage, wherein the intermediate stage is configured to decouple the mixer and the programmable gain stage.
Zero if transmitter with decoupling between mixer and programmable gain stage
A system includes a Zero IF transmitter having a mixer and a programmable gain stage. The Zero IF transmitter also includes an intermediate stage between the mixer and the programmable gain stage, wherein the intermediate stage is configured to decouple the mixer and the programmable gain stage.
ZERO IF TRANSMITTER WITH DECOUPLING BETWEEN MIXER AND PROGRAMMABLE GAIN STAGE
A system includes a Zero IF transmitter having a mixer and a programmable gain stage. The Zero IF transmitter also includes an intermediate stage between the mixer and the programmable gain stage, wherein the intermediate stage is configured to decouple the mixer and the programmable gain stage.
Electronic arrangement and vector network analyzer characterized by reduced phase noise
An electronic arrangement and method for providing a signal characterized by reduced phase noise having a signal source for providing a stimulus signal, a modulator coupled to the signal source for generating a modulated signal as function of the stimulus signal and a local oscillator signal, and a mixer combining the stimulus and modulated signals to generate a mixed signal that includes a component characterized by a mathematical difference of the stimulus signal and the modulated signal. The modulated signal is substantially identical to the stimulus signal and offset by a frequency of the local oscillator signal, so that the difference component of the mixed signal results in a local oscillator signal wherein the stimulus signal phase noise generated by the signal source has been mathematically cancelled.