Oki Electric Industry Co., Ltd.

Yuasa Corporation

Toshihisa Shimizu

Akio Toba

Shigeru Sano

Gunji Kimura

The present invention provides an internal wrap test circuit in a radio equipment which is capable of conducting an internal wrap test, which radio equipment including two transmitting systems in which a transmission signal is amplified by a power amplifier and the amplified transmission signal is outputted in such a manner as to be changed over by a changeover switch to first and second circulators respectively connected to a first antenna and a second antenna, and two receiving systems in which received signals inputted through the first and second antennas are respectively transmitted to a first low noise amplifier and a second low noise amplifier via said first and second circulators, respectively, wherein the internal wrap test circuit includes a local oscillator which is connected to the power amplifier and to the first and second low noise amplifiers so as to control each gain of the power amplifier and the first and second low noise amplifiers, and the transmission signal is lowered to a fixed level to be made into a received signal by using each backward path of the transmission changeover switch and the first and second circulators.

Internal wrap test circuit in radio equipment and test method thereof

A quasi-resonant PWM inverter performs stable resonant operation utilizing a simple control system and a highly efficient inverter operation. A first condenser is connected between a connecting point between first and second main switches and to the first side of the first main switch. A second condenser is connected between the connecting point and the second side of the second main switch. The respective first and second sides of the first main switch and second main switch are connected to a DC power source having a first dividing point for the first potential and a second dividing point for the second potential. A terminal of a first auxiliary switch is connected to the first dividing point; and a terminal of a second auxiliary switch is connected to the second dividing point. A reactor is connected between the connecting points of the first and second auxiliary switches and the first and second main switches.

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Tokyo, Japan

Toshihisa Shimizu