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.
Abstract:
Provided is a polar modulation apparatus capable of performing power limit with a simple configuration even when controlling a transmission power and increasing the transmission signal output power control range. A polar modulation device (1) includes an amplitude limit unit (6) for limiting an amplitude component of an amplitude signal, a D/A converter (7) for converting an inputted digital signal into an analog signal, a power control unit (8) for performing power control so that the inputted signal is an output signal based on the power control signal, a voltage control circuit (9) for supplying voltage to an amplitude modulator (11) according to the output signal from the power control unit (8), an angle modulator (10) for performing angle modulation according to a phase signal, and an amplitude modulator (11) for performing amplitude modulation on the signal subjected to angle modulation, according to the voltage supplied from the voltage control circuit (9).
Abstract:
Provided is a frequency modulation circuit 1 for outputting a highly precise frequency-modulated signal regardless of variation in a characteristic of a VCO 15. A correction value calculation section 17 calculates a correction value Vt2 based on a voltage value (Vtx−Vt1) resulting from subtracting a control voltage Vt1, which is generated by a control voltage generation section 11, from a control voltage Vtx at which a sensitivity of the VCO 15 is maximized. A variable amplifier 18 amplifies the correction value Vt2. An addition section 13 outputs a control voltage Vt3, which results from adding the amplified correction value Vt2 to the control voltage Vt1, to the VCO 15 via a DAC 14.
Abstract:
Provided is a transmission circuit which is capable of compensating for an offset voltage and a sensitivity characteristic of a PA, and operating with low distortion and high efficiency. A regulator 18 supplies, to a PA 201, a voltage which is controlled in accordance with an amplitude signal to which a first offset value has been added. A regulator 19 supplies, to a PA 202, a voltage which is controlled in accordance with an amplitude signal to which a second offset value has been added. The PA 201 amplifies, in accordance with the voltage supplied from the regulator 18, a phase-modulated signal outputted from a phase modulator 13. The PA 202 amplifies, in accordance with the voltage supplied from the regulator 19, an output signal of the PA 201. A digital block 11 controls the first and second offset values in accordance with temperature information T measured by a temperature measuring section 21.
Abstract translation:提供了能够补偿PA的偏移电压和灵敏度特性并且以低失真和高效率运行的传输电路。 调节器18向PA 201提供根据已经添加了第一偏移值的幅度信号来控制的电压。 调节器19向PA 202提供根据已经添加了第二偏移值的幅度信号来控制的电压。 PA 201根据从调节器18提供的电压,放大从相位调制器13输出的相位调制信号。 PA 202根据从调节器19提供的电压来放大PA201的输出信号。 数字块11根据由温度测量部分21测量的温度信息T来控制第一和第二偏移值。
Abstract:
A transmission circuit is provided which can quickly and accurately control an output power of a transmission signal even when the transmission signal is output at a high modulation rate and in a wide dynamic range. A switching control section controls a modulation method changing section to change a modulation method of a modulated signal generating section to a modulation method having a narrow dynamic range before controlling a switching section to switch amplification sections. An output adjustment control section controls output adjusting sections so that a difference in level between a transmission signal which is smoothed by a smoothing circuit and is before the amplification sections are switched, and a transmission signal which is after the amplification sections are switched, is caused to be smaller than a predetermined difference threshold value, when the modulated signal generating section operates in the modulation method having the narrow dynamic range.
Abstract:
Provided is an FM modulator capable of measuring an f-V characteristic of a voltage controlled oscillator in a reduced time period. Therefore, a characteristic measurement time control section 110 notifies a correction section 108 of a time at which a measurement of the f-V characteristic of a voltage controlled oscillator 103 is to be started and a time at which the measurement of the f-V characteristic of the voltage controlled oscillator 103 is to be ended while a carrier wave frequency is being changed to a predetermined frequency. Thus, the correction section 108 is capable of measuring the f-V characteristic of the voltage controlled oscillator 103 in a reduced time period.
Abstract:
A wireless transmission apparatus of multi-mode operation with superior power efficiency is provided. Switches (115 and 117) are switched over in such a manner that a modulation signal outputted from a wireless GSM/EDGE (UB) signal formation circuit (101-3) of a high-frequency signal processing circuit (101) is outputted to a high-frequency power amplifier (104) at the time of output of a GSM modulation signal, and is outputted to a high-frequency amplifier (105) at the time of output of an EDGE modulation signal. As a result, the EDGE modulation signal is power amplified using a high-frequency power amplifier (105) for an UMTS modulation signal use that is compatible with regards to the EDGE modulation signal and the maximum output power and presence or absence of envelope fluctuation. It is therefore possible to amplify the EDGE modulation scheme wireless signal with high efficiency.
Abstract:
A semiconductor device includes: a semiconductor substrate in which a semiconductor element is formed; a multilayer structured wiring layer that is provided on the semiconductor substrate, the wiring layer forming a structure connected with the semiconductor element; a spiral inductor that is formed in at least one layer of the wiring layer; and a connection terminal formed in an uppermost layer of the wiring layer for establishing connection from the wiring layer to an outside such as a printed board. A shielding wiring pattern is disposed between the spiral inductor and the connection terminal, the shielding wiring pattern functioning as an electromagnetic shield for the uppermost layer of the wiring layer. The shielding wiring pattern absorbs a change in electrical field caused by a potential change in the connection terminal, providing a shielding structure which suppresses the superposing of noise and an unnecessary signal onto the spiral inductor from the connection terminal.
Abstract:
An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.