Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Taichi Ikedo

Masakatsu Maeda

Akihiko Matsuoka

Kaoru Ishida

Masaharu Udagawa

Mamoru Arayashiki

A reference voltage adjustment unit () calculates gain from a DA converter () to an offset calculating unit () by detecting the output of the offset calculating unit (), adjusts the reference voltage (V) from a reference voltage generation unit () so that the value becomes a predetermined value, and feeds the post-adjustment reference voltage (V) to the DA converter () and offset calculating unit (). Due to this, the gain from the DA converter () to the offset calculating unit () can be corrected. Fluctuation in the lower limit level of the output of a differential-to-single conversion unit () can be minimized as a result, so, the addition of unnecessary offset to the amplitude data at the amplifier unit () can be minimized. Thus, deterioration in modulation characteristics when the amplitude control unit () takes a differential circuit configuration can be minimized.

Amplitude control circuit, polar modulation transmission circuit, and polar modulation method

An amplitude modulator comprises: a signal processing section for receiving a source signal for wide bandwidth use, splitting the source signal into two source signals for lower frequency use and for higher frequency use, respectively, signal processing the two source signals individually, and outputting a lower-frequency-use source signal and a higher-frequency-use source signal; a first modulation section for modulating the lower-frequency-use source signal and outputting a lower-frequency-use modulation signal; a second modulation section for modulating the higher-frequency-use source signal and outputting a higher-frequency-use modulation signal; a synthesis output section for inputting the lower-frequency-use modulation signal to a first input terminal, the input thereof causing extraction of only a lower-frequency component, for inputting the higher-frequency-use modulation signal to a second input terminal, the input thereof causing extraction of only a higher-frequency component, for synthesizing the higher-frequency component and the lower-frequency component, and for outputting a modulated signal corresponding to the source signal for wide bandwidth use, to a next step.

Amplitude modulator

The amplitude control circuit of the present invention can reduce output noise and suppress a decrease in reception sensitivity. An amplitude control section (), which is an amplitude control circuit, is provided with: a DA converter () that converts amplitude data into differential amplitude signals and outputs the differential amplitude signals; a level control section () that controls the levels of the differential amplitude signals according to transmission power information P; and an offset calculating section () that assigns the DC voltage based upon transmission power information P to the differential amplitude signals subjected to level control in the level control section ().

Amplitude control circuit, polar modulation transmission circuit and polar modulation method

Provided is a power voltage forming device which can correct an offset voltage of a high-frequency power amplifier without degrading distortion characteristic of a high-frequency power amplifier. The power voltage forming device () includes: a level adjusting unit () which adjusts the level of input data subjected to analog conversion, according to an output level control value for controlling the output level of the high-frequency power amplifier (); an analog adder () which performs analog addition of the offset data subjected to the analog conversion, to the signal after the level adjustment; a digital adder () which performs digital addition of the offset data to the input data before the analog conversion; and a selection unit () which selects whether to perform addition by the analog adder () or addition by the digital adder () according to the output level control value.

Power supply voltage forming device and polar modulation transmission device

A transmission modulation apparatus capable of dealing with characteristic variations of a high-frequency power amplifier without always forming an amplitude loop. Transmission modulation apparatusis configured with level detectorthat receives input of a level detection control signal and detects the output signal of high-frequency power amplifier, and offset voltage correcting sectionthat corrects an offset voltage using collinear approximation including a first point where the relationship between the power supply voltage value and the output voltage starts to shift from linear to non-linear based on an output signal of level detectorand a second point where output voltage is a minimum. Offset voltage correction is adaptively executed, and linearity between the voltage value of the baseband amplitude signal and the output voltage of high-frequency power amplifierwhen the voltage value of the baseband amplitude signal is low is compensated.

Transmission modulation apparatus

A transmission circuit operates with high efficiency and low distortion. An amplitude and phase extraction section extracts amplitude data and phase data from input data. A phase modulation section phase-modulates the phase data to output a resultant signal as a phase-modulated signal. An amplifier section amplifies the phase-modulated signal to output a resultant signal as a transmission signal. An amplitude control section supplies, to the amplifier section, a voltage controlled in accordance with an AC component represented by a fluctuation component of the amplitude data and a DC component represented by an average value level of the fluctuation component of the amplitude data.

Transmission circuit and communication device

A quantizer, and a plurality of down-samplers-to-N down-sampling the quantized output at a speed of (1/N) of the sampling rate of the quantizerand shifting the respective phases by (360/N) degrees so as to provide a latched output, are provided. As a result, it is possible to carry out the same operation as for a polyphase quantizer using the down-samplers-to-N with a small circuit scale, while avoiding the variations in characteristics that occur as a result of using a polyphase quantizer.

Amplifier apparatus, polar modulation transmission apparatus and wireless communication apparatus

Linear transmission modulation apparatushas high frequency amplifierthat amplifies the high frequency phase modulation signal of a high frequency signal and power source voltage controllerthat amplifies the baseband amplitude modulation signal of the high frequency signal. Power source voltage controllerhas delta sigma amplifierthat performs delta sigma amplifying of the baseband amplitude modulation signal and generates a delta sigma amplification signal and delta amplifierthat performs delta amplifying of the baseband amplitude modulation signal and generates a delta amplification signal. In response to a modulation mode switching control signal that indicates as to whether or not the amplitude modulation signal fluctuates, one of delta sigma amplifierand delta amplifieroperates and sends out an output.

A polar modulation transmission apparatus is provided which can adjust synchronization between an amplitude signal and phase signal in a simple configuration accurately and automatically. A polar signal generation circuitsends an amplitude signal and phase signal for synchronization adjustment to transmission lines of these signals, incorporates the amplitude signal and phase signal for synchronization adjustment output from low pass filterswhich are final stage circuits that process the respective signals in their baseband signal states into a delay difference detection circuit, a synchronization adjustment control circuitobtains a synchronization adjustment value at which the delay difference between the signals is eliminated based on the delay difference detection result and a synchronization adjustment circuitgives delays corresponding to the synchronization adjustment value to the respective signals.

Growing community of inventors

Kanagawa, Japan

Taichi Ikedo