The present disclosure relates to a 5th generation (5G) or pre-5G communication system for supporting a higher data transmission rate than a 4th generation (4G) communication system such as Long-Term Evolution (LTE). The present disclosure provides a device for variable signal attenuation equipped in a stack-up structure inside an RFIC. The device for signal attenuation comprises: a first transmission line positioned on a first layer inside the RFIC; a second transmission line positioned on a second layer, which is adjacent to the first layer, and electromagnetically coupled to the first transmission line; and a control unit. The first transmission line comprises an impedance control unit on one side. The control unit can variably control the impedance control unit.

A wireless transceiver includes: a switching amplifier having first, second and power ports; and a current provider. The current provider provides a current to the power port, and further provides an impedance to the power port such that an impedance of the switching amplifier at the second port matches an impedance of an antenna coupled to the second port. The switching amplifier simultaneously amplifies a transmit signal input received at the first port to generate an output signal at the second port for receipt by the antenna, and mixes a receive signal received at the second port from the antenna with the transmit signal input to generate, at the power port, another output signal having a frequency lower than that of the receive signal.

A wireless transceiver includes: a switching amplifier having first, second and power ports; and a current provider. The current provider provides a current to the power port, and further provides an impedance to the power port such that an impedance of the switching amplifier at the second port matches an impedance of an antenna coupled to the second port. The switching amplifier simultaneously amplifies a transmit signal input received at the first port to generate an output signal at the second port for receipt by the antenna, and mixes a receive signal received at the second port from the antenna with the transmit signal input to generate, at the power port, another output signal having a frequency lower than that of the receive signal.

The present invention relates to a capacitance multiplier topology suitable for both positive and negative capacitance multiplication having a minimum configuration consisting of a current feedback amplifier (CFOA), two resistors and a reference capacitor, with each C-multiplier having a respective capacitance amplification constant k which is externally adjustable. Such a capacitance multiplier has less parasitic components, occupies a smaller chip area with higher simulated capacitance value.

A wireless transceiver includes: a switching amplifier having first, second and power ports; and a current provider. The current provider provides a current to the power port, and further provides an impedance to the power port such that an impedance of the switching amplifier at the second port matches an impedance of an antenna coupled to the second port. The switching amplifier simultaneously amplifies a transmit signal input received at the first port to generate an output signal at the second port for receipt by the antenna, and mixes a receive signal received at the second port from the antenna with the transmit signal input to generate, at the power port, another output signal having a frequency lower than that of the receive signal.

A wireless transceiver includes: a switching amplifier having first, second and power ports; and a current provider. The current provider provides a current to the power port, and further provides an impedance to the power port such that an impedance of the switching amplifier at the second port matches an impedance of an antenna coupled to the second port. The switching amplifier simultaneously amplifies a transmit signal input received at the first port to generate an output signal at the second port for receipt by the antenna, and mixes a receive signal received at the second port from the antenna with the transmit signal input to generate, at the power port, another output signal having a frequency lower than that of the receive signal.

An impedance matching device comprising a variable reactor having a main winding and control winding, wherein a generated magnet field in the core is an AC magnetic field with a magnitude exceeding a value to settle a deviation between a control target value for impedance matching and a feedback value, by changing the magnitude of the generated magnetic field by changing a control current passing through the control winding, thereby controlling inductance of the variable rector to be a predetermined value to perform impedance matching, the response delay in the impedance matching is reduced by reducing a response delay in the inductance variation of the variable reactor.

An impedance matching device comprising a variable reactor having a main winding and control winding, wherein a generated magnet field in the core is an AC magnetic field with a magnitude exceeding a value to settle a deviation between a control target value for impedance matching and a feedback value, by changing the magnitude of the generated magnetic field by changing a control current passing through the control winding, thereby controlling inductance of the variable rector to be a predetermined value to perform impedance matching, the response delay in the impedance matching is reduced by reducing a response delay in the inductance variation of the variable reactor.

The invention relates to an ultrasonic measuring system (10), in particular for measuring distance and/or as a parking aid in vehicles, having an electroacoustic ultrasonic transducer (12) which has a oscillating element (14), does not have a voltage converter, can be alternately operated as an ultrasonic transmitter and an ultrasonic receiver and has a signal connection (16), which is used either as an input or as an output of the ultrasonic transducer (12), and an earth connection (18) which is connected to earth, and a control and evaluation unit (20) for exciting the oscillating element (14) of the ultrasonic transducer (12) to emit ultrasonic waves for operating the ultrasonic transducer (12) during a transmission interval for the purpose of subsequently deactivating the excitation of the oscillating element (14) and attenuating the latter during a decay phase and for receiving and processing ultrasonic waves in a reception interval. The control and evaluation unit (20) has a bridge circuit (28) which is connected to a DC supply voltage (80) and has controllable switches (30 to 40) and a charge storage capacitance (42), the polarity of which can be reversed and which is intended to alternately output a positive and a negative excitation voltage for the signal connection (16) of the ultrasonic transducer (12) during the transmission interval. The control and evaluation unit (20) outputs a voltage pulse of substantially 0 V at the end of the transmission interval for the signal connection (16) of the ultrasonic transducer (12).

The invention relates to an ultrasonic measuring system (10), in particular for measuring distance and/or as a parking aid in vehicles, having an electroacoustic ultrasonic transducer (12) which has a oscillating element (14), does not have a voltage converter, can be alternately operated as an ultrasonic transmitter and an ultrasonic receiver and has a signal connection (16), which is used either as an input or as an output of the ultrasonic transducer (12), and an earth connection (18) which is connected to earth, and a control and evaluation unit (20) for exciting the oscillating element (14) of the ultrasonic transducer (12) to emit ultrasonic waves for operating the ultrasonic transducer (12) during a transmission interval for the purpose of subsequently deactivating the excitation of the oscillating element (14) and attenuating the latter during a decay phase and for receiving and processing ultrasonic waves in a reception interval. The control and evaluation unit (20) has a bridge circuit (28) which is connected to a DC supply voltage (80) and has controllable switches (30 to 40) and a charge storage capacitance (42), the polarity of which can be reversed and which is intended to alternately output a positive and a negative excitation voltage for the signal connection (16) of the ultrasonic transducer (12) during the transmission interval. The control and evaluation unit (20) outputs a voltage pulse of substantially 0 V at the end of the transmission interval for the signal connection (16) of the ultrasonic transducer (12).