Abstract:
PROBLEM TO BE SOLVED: To enable preventing distortion of a waveform by applying a sufficient idle current to a transistor for amplification in the vicinity of the maximum level of an output power, and to enable improving power efficiency in a region where the output power is low, in a high-frequency power amplifier circuit for giving a bias to the transistor for amplification by a current mirror system. SOLUTION: A detection circuit (240) is provided which consists of a detection transistor (Q1) having a control terminal receiving the AC component of the input signal of the amplification transistor (213) of the final stage, current mirror circuits (Q2, Q3) for transferring a current flowing to the transistor, and a current-voltage converting means (Q4) for converting a current of the transfer side of the current mirror circuits into a voltage. A voltage from a bias circuit (230) for generating the bias voltage of the amplification transistor is applied to the control terminal of the detection transistor of the detection circuit, and the output of the detection circuit is applied to the control terminal of the amplification transistor of the final stage. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To further reduce power consumption at the time of a small signal output. SOLUTION: When a radio signal is transmitted to a small cell according to an amplifying operation mode designated by a main controller 10 in an amplifying control circuit 120, a feeding control circuit 121 is controlled to stop feeding to a main amplifier 101 and to feed to an error amplifier 110 in stead of the main amplifier 101. Also, switchover switches 112 and 113 are controlled to switch a movable point to a fixed point "b" side. Thus, the radio signal amplified by the error amplifier 110 is transmitted as the radio signal of power corresponding to the small cell. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
L'invention concerne un dispositif d'amplification de puissance radiofréquence (RF) et/ou hyperfréquence, notamment pour terminal de radiocommunication, comprenant des moyens de blindage dudit dispositif et des moyens de contrôle d'une puissance délivrée en sortie dudit dispositif, comprenant une boucle d'asservissement en puissance présentant des moyens de référence, des moyens de détection, des moyens de comparaison et des moyens d'amplification de puissance. Selon l'invention, lesdits moyens de contrôle comprennent également au moins un capteur d'une énergie rayonnée au sein dudit dispositif.
Abstract:
The variable power supply (12) to an amplifier (10) in an electrical circuit is dynamically controlled through the use of a lookup table (14) responsive to one or more operating conditions of the electrical circuit. The lookup table is indexed by one or more of the operating conditions and the amount of amplification to be applied to an input signal to the amplifier is determined. One embodiment of the invention comprises a television transmitter circuit including a power amplifier circuit capable of amplifying a variable frequency COFDM or 8VSB input signal (11) where the amount of amplification applied to the input signal is dynamically controlled through the use of a lookup table as a function of the frequency of the input signal.
Abstract:
While level of the inputted analog signal is adjusted according to a set analog gain value and then analog-digital converted and outputted, when an automatic compensation is on and a difference of the analog gain value and a target value is compensated by level adjustment in a digital amplifier, the analog gain value is displayed by a gain knob (161), and in response to an operation to turn on the automatic compensation, a present value of the analog gain value at that time is displayed as a target gain value by a mark (162a) near the analog gain value, and in response to an operation to turn off the automatic compensation, display of the target gain value is erased.