摘要:
Provided is a method of generating a driving signal for driving a dual mode supply modulator for a power amplifier. The method includes obtaining an envelope of a complex baseband signal to be transmitted, comparing the envelope of the complex signal with a preset threshold value, when a current envelope of the complex signal is the preset threshold value or greater or when there is a result having the preset threshold value or greater in previous N comparisons, outputting a digital board output signal configured with a first logic level through a digital-to-analog converter; and when the current envelope of the complex signal is smaller than the preset threshold value and when there is no result having the preset threshold value or greater in the previous N comparisons, outputting a digital board output signal configured with a second logic level through the digital-to-analog converter.
摘要:
A digital polar modulator (DPM) for transforming a baseband signal into a modulated digital modulator output signal comprises an input unit and two low-pass delta-sigma modulators, a first one being connected downstream from the first input part and configured to provide at its output a first pulse train in dependence on an amplitude- modulating baseband signal component, and a second one being connected downstream from the second input part and configured to provide at its output a multilevel quantized signal in dependence on a phase modulating baseband signal component; a multiphase generator, which is configured to provide a set of square-wave carrier signals having a common carrier frequency and exhibiting discrete phase shifts with respect to each other; a multiplexer, which is configured to provide a multiplexer output signal that is formed by switching, in dependence on a signal received at a select input as a function of time, between selected ones of the carrier signals; and a combiner unit.
摘要:
A digital polar modulator (DPM) for transforming a baseband signal into a modulated digital modulator output signal comprises an input unit and two low-pass delta-sigma modulators, a first one being connected downstream from the first input part and configured to provide at its output a first pulse train in dependence on an amplitude- modulating baseband signal component, and a second one being connected downstream from the second input part and configured to provide at its output a multilevel quantized signal in dependence on a phase modulating baseband signal component; a multiphase generator, which is configured to provide a set of square-wave carrier signals having a common carrier frequency and exhibiting discrete phase shifts with respect to each other; a multiplexer, which is configured to provide a multiplexer output signal that is formed by switching, in dependence on a signal received at a select input as a function of time, between selected ones of the carrier signals; and a combiner unit.
摘要:
A method of checking an error vector magnitude of transmitter in accordance with some embodiments of the inventive concept may include dividing a transmission baseband signal which the transmitter transmits into a plurality of processing units; performing a transmitter function and an ideal receiver function with respect to each of the plurality of processing units; generating a reception baseband signal by recombining a processing result of each of the plurality of processing units; and calculating an error vector magnitude (EVM) by comparing the transmission baseband signal with the reception baseband signal. A simplified method of checking an error vector magnitude of transmitter in accordance with some embodiments of the inventive concept may include generating symbols composed of only pilots; generating symbol composed of only data; and checking an error vector magnitude (EVM) using the all the symbols.
摘要:
Provided is an amplifier structure. The amplifier structure includes a delta-sigma modulator, an up converter, a power amplifier, and a band-pass filter. The delta-sigma modulator receives an IF signal to delta-sigma modulate the IF signal. The up converter up-converts a frequency of the delta-sigma modulated signal with an LO signal. The power amplifier amplifies a power of the up-converted signal. The band-pass filter filters the amplified signal of a selected band. The amplifier structure performs the delta-sigma modulation operation on an IF input signal, and thus can considerably decrease a delta-sigma modulation operation speed compared to a typical amplifier structure and moderate the specification in implementing a power amplifier.
摘要:
The present invention relates to tricarbonyl technetium-99m or rhenium-188 labeled cyclic RGD derivatives, a preparation method thereof, and a pharmaceutical composition containing the derivative as an active ingredient for use in the diagnosis or treatment (radiotherapy) of angiogenesis-related diseases. The tricarbonyl technetium-99m or rhenium-188 labeled cyclic RGD derivatives of the present invention has a high subnanomolar affinity to integrin αvβ3 (also called as a vitronectin receptor) that is activated in an angiogenic action induced by a tumor, and acts exclusively upon cancer cells having selectively activated integrin αvβ3 because of a substantially low intake into the liver and intestines.
摘要:
A radio frequency receiver of the present invention removes out-of-band jamming signals and interference signals without SAW filters. The radio frequency receiver includes: a low noise amplifier amplifying a signal received through an antenna; a second order intermodulation cancellation unit removing second order intermodulation caused by an out-of-band jamming or interference signal included in the signal output from the low noise amplifier; a passive mixer unit converting a frequency of the signal output from the second order intermodulation cancellation unit; and a low pass filter unit removing an out-of-band jamming or interference signal included in the signal output from the passive mixer unit and delivering the signal with the out-of-band jamming or interference signal removed therefrom to a transimpedance amplifier.
摘要:
A radio frequency receiver of the present invention removes out-of-band jamming signals and interference signals without SAW filters. The radio frequency receiver includes: a low noise amplifier amplifying a signal received through an antenna; a second order intermodulation cancellation unit removing second order intermodulation caused by an out-of-band jamming or interference signal included in the signal output from the low noise amplifier; a passive mixer unit converting a frequency of the signal output from the second order intermodulation cancellation unit; and a low pass filter unit removing an out-of-band jamming or interference signal included in the signal output from the passive mixer unit and delivering the signal with the out-of-band jamming or interference signal removed therefrom to a transimpedance amplifier.
摘要:
The present invention relates to tricarbonyl technetium-99m or rhenium-188 labeled cyclic RGD derivatives, a preparation method thereof, and a pharmaceutical composition containing the derivative as an active ingredient for use in the diagnosis or treatment (radiotherapy) of angiogenesis-related diseases. The tricarbonyl technetium-99m or rhenium-188 labeled cyclic RGD derivatives of the present invention has a high subnanomolar affinity to integrin αvβ3 (also called as a vitronectin receptor) that is activated in an angiogenic action induced by a tumor, reflects a high tumor image of the tricatvonyl technetium-99m labeled cyclic RGD derivative after initial intake in an animal in which cancer cells are transplanted, and acts exclusively upon cancer cells having selectively activated integrin αvβ3 because of a substantially low intake into the liver and intestines, compared to existing known radioactive isotope labeled cyclic RGD derivatives. These results show that the rhenium-188 labeled derivative, a therapeutic nuclide using the same precursor as used in the technetium-99m labeling, effectively inhibits the growth of a tumor and demonstrates therapeutic efficacy when administered via tail vein injection to an animal model bearing tumor, compared to a case where only saline has been injected, thereby making it useful as a medicine for the diagnosis or treatment of angiogenesis-related diseases.
摘要:
Disclosed is a front-end apparatus of an RF transceiver connected with an antenna in a wireless communication system. The front-end apparatus of an RF transceiver using radio-frequency passive elements includes: a plurality of band pass filters configured a transmission signal and a reception signal; a first circulator configured to output a first transmission signal to a second terminal and output a second reception signal input; a second circulator configured to output a second transmission signal input into the first terminal to the second terminal and output a first reception signal input into the second terminal to the third terminal; a passive directional double pole and double throw switch configured to process a route to be changed depending on directions of an input and an output; a first antenna configured to transmit the first transmission signal; and a second antenna configured to transmit the second transmission.