A mixer includes a load portion connected between an input terminal of a first power voltage and an output terminal of the radio frequency transmit signal and configured to adjust a magnitude of the radio frequency transmit signal, a first switching unit connected to an output terminal of the radio frequency transmit signal, and configured to perform a first switching operation in response to a plurality of local oscillation signals, and a second switching unit connected between the first switching unit and an input terminal of a second power voltage, lower than the first power voltage, and configured to perform a second switching operation in response to a plurality of baseband signals, the plurality of local oscillation signals include an I+ baseband signal, an I baseband signal, a Q+ baseband signal, and a Q baseband signal, and the second switching unit includes a first branch performing a switching operation under control of the I+ baseband signal and the Q+ baseband signal, a second branch performing a switching operation under control of the I baseband signal and the Q baseband signal, a third branch performing a switching operation under control of the Q+ baseband signal and the I baseband signal, and a fourth branch performing a switching operation under control of the Q baseband signal and the I+ baseband signal.

The disclosure relates to technology for an apparatus having a current conveyer comprising a first stage having a first differential input, and a second stage having a second differential input. The first and second stages are configured to operate in a push-pull mode to provide an output signal at a current conveyer output between the first stage and the second stage. The apparatus has a first frequency mixer configured to generate a first mixer signal based on an input signal and an oscillator signal having a first frequency. The first frequency mixer is configured to provide the first mixer signal to the first differential input. The apparatus has a second frequency mixer configured to generate a second mixer signal based on the input signal and a second oscillator signal having the first frequency. The second frequency mixer is configured to provide the second mixer signal to the second differential input.

The disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as long term evolution (LTE). An operation method of a device for upconversion in a wireless communication system is provided. The method includes receiving a first local oscillator (LO) signal, generating a second LO signal, based on the first LO signal and cross-coupled latches, receiving an input signal, generating an upconverted frequency, based on the second LO signal and the input signal, generating an output signal obtained by processing a harmonic component included in the upconverted frequency, and transmitting the generated output signal.

A wireless receiver and a wireless reception method provide: to determine a gain based on a first resistor having a first temperature characteristic and a second resistor having a second temperature characteristic different from the first resistance; to output an output of the first resistor and an output of the second resistor, or a ratio between the output of the first resistor and the output of the second resistor; and to switches the gain of the first circuit based on the outputs or the ratio between the outputs.

Proposed is related to a quadrature passive mixer and a frequency down-converter for enhancing an input referred second-order intercept point (IIP2). More particularly, proposed is related to a quadrature passive mixer and a frequency down-converter for enhancing the IIP2 capable of improving the IIP2 by reducing a mismatch component of a mixer block used for frequency downconversion of a wireless communication system. Here, the frequency down-converter for improving the IIP2 according to the embodiment of the present invention includes an RF quadrature signal generator, an LO IQ signal generator, a 25% LO signal generator, an LO buffer, an I-quadrature mixer, and a Q-quadrature mixer. In addition, the I-quadrature mixer and the Q-quadrature mixer receive RF quadrature signals from the RF quadrature signal generator and selectively downconvert and output the RF quadrature signals according to the 25% duty-cycle LO signals applied from the LO buffer.

A mixer includes: a VGA (12) configured to amplify one of divided two portions of an input signal at a gain of cos ; a VGA (13) configured to amplify another one of the divided two portions of the input signal at a gain of sin ; an IQ generator (15) configured to input an LO wave, and output an LO wave in phase with the input LO wave and an LO wave having a phase difference of 90 with respect to the input LO wave; a mixer (16) configured to input the signal output from the VGA (12) and the LO wave which is output from the IQ generator (15) , to output an RF signal; a second mixer (17) configured to input the signal from the VGA (13) and the LO wave which is output from the IQ generator, to output an RF signal; and a combiner (18).

A transmitter generates programmable upstream and downstream signal pulses for transmission through a fluid whose flow rate is being measured. A receiver receives the upstream and downstream signal pulses and stores digital representations of the pulses. A multiple pass algorithm such as a time domain windowing function and/or an algorithm that equalizes amplitude operates on the stored digital representations prior to demodulation. A quadrature demodulator generates in-phase and quadrature components of the digital representations and an arctangent function using the in-phase and quadrature components determines angles associated with the upstream and downstream signal pulses. The difference between the upstream and downstream angles, from which a difference in time of flight between the upstream and downstream signal pulses can be derived, is used to determine flow rate.

The disclosure relates to technology for an apparatus having a current conveyer comprising a first stage having a first differential input, and a second stage having a second differential input. The first and second stages are configured to operate in a push-pull mode to provide an output signal at a current conveyer output between the first stage and the second stage. The apparatus has a first frequency mixer configured to generate a first mixer signal based on an input signal and an oscillator signal having a first frequency. The first frequency mixer is configured to provide the first mixer signal to the first differential input. The apparatus has a second frequency mixer configured to generate a second mixer signal based on the input signal and a second oscillator signal having the first frequency. The second frequency mixer is configured to provide the second mixer signal to the second differential input.

Embodiments of communications devices and methods for operating a communications device are described. In an embodiment, a communications device includes a complex multiplier configured to multiply a first input complex signal with a second input complex signal to generate an output complex signal, an amplifier configured to amplify an imaginary part of the output complex signal to generate an amplification result, a delay element configured to delay a rotation angle signal that is related to the second input complex signal, and a subtractor configured to subtract the amplification result from the delayed rotation angle signal to generate the rotation angle signal. Other embodiments are also described.

A down-conversion mixer includes a converting-and-mixing module and a load module. The converting-and-mixing module performs voltage-to-current conversion and mixing with first and second differential oscillatory voltage signal pairs upon a differential input voltage signal pair to generate first and second differential mixed current signal pairs. The load module includes two RL circuits and a negative resistance providing circuit that cooperate to convert the first and second differential mixed current signal pairs into first and second differential mixed voltage signal pairs. Each RL circuit includes two variable resistors, and an inductor connected between the variable resistors.