Abstract:
Provided is a transmitter apparatus including: a signal conversion section for, in polar modulation, converting input data into an amplitude-component signal and a phase-component signal, and in quadrature modulation, converting input data into an in-phase component signal and a quadrature component signal; a carrier wave generation section for outputting a carrier wave; a mixer section for, in quadrature modulation, generating a quadrature modulation signal; a regulator for, in polar modulation, outputting a supply voltage control signal; and a power amplifier for, in polar modulation, amplifying the supply voltage control signal and superimposing the resultant signal onto the carrier wave, thereby generating a transmission signal, wherein in polar modulation, the carrier wave generation section outputs the carrier wave modulated with respect to phase component, and in quadrature modulation, the carrier wave generation section outputs the carrier wave that is yet to be modulated.
Abstract:
When switching the mode of a power amplifier between compressed mode and uncompressed mode, accurate transmission power control is realized. A transmission power control method includes setting a power setting value of mode to switch to, such that an inter-mode output power error is canceled (equal to step ST21), calculating an intra-mode output power error from the power setting value of the mode to switch to (equal to step ST23), calculating a gain linearity value based on the power setting value of the mode to switch to and an output power error of the intra-mode (equal to step ST24), and resetting the power setting value of the mode to switch to based on the gain linearity value (equal to steps ST25 and 26).
Abstract:
A current control circuit (5) recognizes whether or not a transmission signal is transmitted based on a control signal outputted from a transmission signal control circuit (4). When the transmission signal is transmitted, the current control circuit (5) controls a current flowing into a reception circuit (3) in accordance with control information representing any of at least two modes where the transmission signal is transmitted. When no transmission signal is transmitted, the current control circuit (5) controls the current flowing into the reception circuit (3) in accordance with control information representing a mode where no transmission signal is transmitted.
Abstract:
A nonlinearity-compensated section has a pre-set compensation table containing a measured value of a voltage vtc, outputted from a loop filter, which is changed accordingly with respect to a change in a voltage vtfc outputted from a frequency controlling section. The nonlinearity-compensated section sets, in the compensation table, the voltage vtfc of an oscillatory frequency oscillated by a VCO and the voltage vtc associated therewith as reference voltages, and creates a look-up table containing voltage differences obtained by subtracting the above-described reference voltages from the voltages vtfc and vtc, respectively. Thereafter, the nonlinearity-compensated section extracts a compensation value corresponding to the voltage vtc actually outputted from the loop filter by means of the look-up table, and adds the compensation value to an input modulated signal adjusted by a multiplier so as to be outputted.
Abstract:
A switching control circuit includes a serial-to-parallel converter, a rewritable storage device, and a decoder. The serial-to-parallel converter performs serial-to-parallel conversion for converting an inputted first control signal into a first parallel signal, and outputs the first parallel signal. The rewritable storage device has a write mode and a read mode selectively switched over in response to a storage mode switching signal, stores therein data of the first parallel signal in the write mode, and outputs the stored data as a second parallel signal in the read mode. In the read mode, the decoder decodes the first control signal and the second parallel signal to generate and output a plurality of element control signals to a plurality of elements, respectively. In the write mode, the decoder holds the plurality of element control signals generated in the read mode.
Abstract:
Provided is a transmission circuit 1 which is capable of precisely compensating for an offset characteristic of an amplitude modulation section 15, and operating with low distortion and high efficiency over a wide output electric power range. A signal generation section 11 outputs an amplitude signal and an angle modulation signal. An amplitude amplifying section 14 inputs, to the amplitude modulation section 15, a signal corresponding to a magnitude of the amplitude signal having been inputted. The amplitude modulation section 15 amplitude-modulates the angle modulation signal with the signal inputted from the amplitude amplifying section 14, and outputs a resultant signal as a modulation signal. The power measuring section 18 measures an output power of the amplitude modulation section 15. An offset compensation section 12 reads an offset compensation value from a memory 13 in accordance with the output power of the amplitude modulation section 15, and adds the read offset compensation value to the amplitude signal.
Abstract:
Provided is a transmission circuit 1 which precisely compensates for an offset characteristic of an amplitude modulation section 15 and which operates with low distortion and high efficiency over a wide output power range. A signal generation section 11 outputs an amplitude signal and an angle-modulated signal. An amplitude amplifying section 14 supplies, to the amplitude modulation section 15, a voltage corresponding to a magnitude of an inputted amplitude signal. The amplitude modulation section 15 amplitude-modulates the angle-modulated signal by the voltage supplied from the amplitude amplifying section 14, thereby outputting a resultant signal as a modulation signal. A temperature measuring section measures a temperature of the amplitude modulation section 15. An offset compensation section 12 calculates an offset compensation value in accordance with a change, in temperature of the amplitude modulation section 15, from the temperature of the amplitude modulation section 15 in an initial state, and adds the calculated offset compensation value to the amplitude signal.
Abstract:
A differential type voltage control oscillator is formed of a differential tank circuit, an oscillation transistor, and a differential variable capacitance circuit. The differential variable capacitance circuit has a configuration wherein at least one pair of varactor diodes are connected in an anti-parallel manner, and are separated by means of a plurality of capacitors in a direct current manner. In addition, a differential control voltage is generated by a charge pump circuit which is controlled by the output of a phase comparator, and the differential control voltage is directly applied across the anodes and the cathodes of the varactor diodes.
Abstract:
An object of the invention is to provide a receiving circuit where the quality of reception can be prevented from deteriorating when the gain changes, so that the good quality of the received signal can be preserved, as well as a receiving apparatus and a transmitting/receiving apparatus using the receiving circuit. In the configuration of the invention, a switch (113) is converted to a short state in response to a change in the gain of a variable gain amplifier (107) by means of a gain control apparatus 112, and thereby, the output terminal of a high pass filter (111) is fixed at a reference voltage and the cutoff frequency of a low pass filter (108) is increased. As a result, the period during which the DC voltage has transient response properties in the low pass filter (108) can be shortened, and this transient response prevented from passing through the high pass filter (111).
Abstract:
A small-size transmission circuit is provided which outputs a transmission signal having high linearity independently of a magnitude of an output power, and operates with high efficiency. A signal generating section generates quadrature data based on input data. A computation section compares an amplitude component of the quadrature data with a predetermined amplitude threshold value, and outputs an amplitude signal, a first phase signal, and a second phase signal. A regulator outputs a voltage controlled depending on the amplitude signal. An angle modulation section and an angle modulation section angle-modulate the phase signal to output first and second angle-modulated signals. An amplitude modulation section and an amplitude modulation section amplitude-modulate the first and second angle-modulated signals using a voltage controlled depending on the amplitude signal to output the angle-modulated and amplitude-modulated signals as a first modulated signal and a second modulated signal. A combining section combines the first and second modulated signals to output a transmission signal.