Matsushita Electric Industrial Co., Ltd.

Ulvac Techno, Ltd.

Yasushi Iwata

Yasufumi Ichikawa

Toshio Obara

Katsunori Fujii

Masanori Ito

Yoshiharu Ishihara

The power supply apparatus for the electrostatic chuck of this invention has: DC power source units for applying DC voltage to electrodes of the electrostatic chuck; and an AC power source unit for causing AC current to flow through an electrostatic capacitance of the electrostatic chuck. Provided that: a circuit for charging an electrode, from DC power source unit, with chuck voltage in order to attract and hold in position the to-be-processed substrate with the electrostatic chuck, be defined as a first circuit and that; a circuit for clearing charges of the to-be-processed substrate be defined as a second circuit, the power supply apparatus further includes switching means for switching between the first circuit and the second circuit. The second circuit is provided with an AC power source unit and a voltmeter for measuring AC voltage.

Power supply apparatus for electrostatic chuck and substrate control method

An antenna selection diversity apparatus capable of shortening, when antennas are switched in frame units, a measuring time of antennas and shortening the time of selecting an optimal antenna from among a plurality of antennas on standby. In this apparatus, an antenna selection section () selects one of three antennas as an antenna in actual use for a period of a plurality of frames consecutively according to selection priority stored in an antenna information storage section () and gives an instruction for selecting one of two antennas on standby as an antenna to be measured once at a period of a plurality of frames to an antenna selection switch (). When the reception level of the antenna in actual use measured by a reception level measuring section () falls below the reception level of the antenna to be measured a predetermined number of times consecutively, the antenna selection section () gives an instruction for selecting the antenna to be measured as the antenna in actual use to the antenna selection switch ().

Antenna selection diversity apparatus and reception method

A constant output signal can be achieved by controlling a gain variable amplifierbased on a level of an output signal which is derived by variably amplifying a receiving signal S(input signal). An AGC output signal Sis detected by a detector circuit, then a detected voltage signal Sis converted into a digital signal by an A/D converterto output it to a CPU. Then, the CPUgenerates a control signal Sbased on the detected voltage signal S, then an A/D converterconverts the control signal Sinto the analogue signal, and then the signal is sent out to the gain variable amplifierto execute gain control. At this time, an RSSI detector portiondetects an RSSI signal Scorresponding to a transmitting signal level from the receiving signal S, and then the CPUsends out the control signal Sstored at the time of preceding execution of the gain control when the RSSI signal Sis reduced below a predetermined threshold value S. In the weak received electric field strength, the control voltage for the gain variable amplifier is prevented reduction, and the proper automatic gain control can be made possible to thus achieve the good receiving characteristics.

Automatic gain control method and device

A constant output signal can be achieved by controlling a gain variable amplifier based on a level of an output signal which is derived by variably amplifying a receiving signal S (input signal). An AGC output signal S is detected by a detector circuit . Then, a CPU generates a control signal S based on a detected voltage signal S . An RSSI detector portion detects an RSSI signal S corresponding to a transmitting signal level from the receiving signal S . The transmitting signal level is compared to a preceding transmitting signal level. The control signal from a preceding execution of the gain control is output if the present control signal is lower than the preceding control signal and the present transmitting signal level is reduced below the preceding transmitting signal level.

At the power-on, a determination section ( ) outputs a switch control signal (m) to a selector switch ( ) to select the output of a sweep signal generator ( ) which generates a voltage sweep signal (h) that increases from the minimum value to the maximum value of the gain control voltage range (p) at the same time, then provides the voltage sweep signal (h) to the variable gain amplifier ( ), and calculates the difference (f) between the level detection value of an output signal (c) and a convergence value (e) and detects a sweep voltage value (j) obtained when (f)&equals;0 and stores the sweep voltage value (j) into memory. After the sweep operation, the sweep voltage value (j) stored in memory is provided as a gain control signal (b) to the variable gain amplifier ( ). Then the primary automatic gain control via the closed loop control system is started.

Automatic gain control method and apparatus, and radio communications apparatus having automatic gain control function

A constant output signal can be achieved by controlling a gain variable amplifier based on a level of an output signal which is derived by variably amplifying a receiving signal S (input signal). An AGC output signal S is detected by a detector circuit , then a detected voltage signal S is converted into a digital signal by an A/D converter to output it to a CPU . Then, the CPU generates a control signal S based on the detected voltage signal S , then an A/D converter converts the control signal S into the analogue signal, and then the signal is sent out to the gain variable amplifier to execute gain control. At this time, an RSSI detector portion detects an RSSI signal S corresponding to a transmitting signal level from the receiving signal S , and then the CPU sends out the control signal S stored at the time of preceding execution of the gain control when the RSSI signal S is reduced below a predetermined threshold value S . In the weak received electric field strength, the control voltage for the gain variable amplifier is prevented reduction, and the proper automatic gain control can be made possible to thus achieve the good receiving characteristics.

When an input signal S is variable-gain-amplified by a variable gain amplifier to obtain a predetermined output signal S , a variable gain control signal S is generated by a detecting circuit , an A/D converter , an adder , and a converting unit . Both a latch circuit and an adder calculate a difference between a variable gain control signal generated during a preceding control operation and a present variable gain control signal. When the difference result is equal to &ldquo;0&rdquo;, a counter counts predetermined stable condition continued time, and thereafter outputs a non-operation setting signal S . Also, the counter sends out the variable gain control signal generated during the preceding control operation to the variable gain amplifier so as to set the detecting circuit , the A/D converter , the adder , and the converting unit into non-operation conditions thereof.

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Shizuoka, Japan

Yasushi Iwata