摘要:
Single sideband (SSB) mixers and methods of extracting a SSB signal, which are capable of outputting a single frequency using a plurality of mixers and a local oscillating frequency without having to implement phase-shifting. In one embodiment, a single sideband (SSB) mixer comprises a first mixer and a second mixer, wherein the first and second mixers multiply an input IF (intermediate frequency) signal by a local IF signal having the same frequency of the input IF signal; a band-pass filter which passes upper sideband signal output from the first mixer; a third mixer which multiplies the upper sideband signals output from the band-pass filter by a LO (local oscillating) signal; a fourth mixer which multiplies the signals output from the second mixer by the LO signal; and a subtraction device that subtracts output signals of the third mixer from output signals of the fourth mixer. Accordingly, a quadrature local oscillator which displaces a phase of a local oscillating signal by 90° at a high frequency is not required. Also, since the SSB mixer applies the same local oscillating frequency signal to each mixer, the rejection characteristics against undesired signals can be achieved to a level of about 70 dB, experimentally.
摘要:
An apparatus and method for receiving RF signals in a RF communication system are provided. The apparatus for receiving RF signals comprises a pre-processing unit for bandpass-filtering a signal received through an external antenna with a predetermined bandwidth and extracting a RF input signal having a desired frequency; a mixing unit for mixing the RF input signal provided from the pre-processing unit with a local oscillation signal having the same frequency as the RF input signal and generating a desired baseband signal; a noise-free-signal amplifying unit for shifting the desired baseband signal to a band that is free of effects due to 1/f noise, amplifying the shifted baseband signal, and re-shifting the amplified signal to the baseband; and a baseband processing unit for selecting a desired channel signal from the amplified baseband signal to be provided from the noise-free-signal amplifying unit and amplifying the selected signal.
摘要:
Single sideband (SSB) mixers and methods of extracting a SSB signal, which are capable of outputting a single frequency using a plurality of mixers and a local oscillating frequency without having to implement phase-shifting. In one embodiment, a single sideband (SSB) mixer comprises a first mixer and a second mixer, wherein the first and second mixers multiply an input IF (intermediate frequency) signal by a local IF signal having the same frequency of the input IF signal; a band-pass filter which passes upper sideband signal output from the first mixer; a third mixer which multiplies the upper sideband signals output from the band-pass filter by a LO (local oscillating) signal; a fourth mixer which multiplies the signals output from the second mixer by the LO signal; and a subtraction device that subtracts output signals of the third mixer from output signals of the fourth mixer. Accordingly, a quadrature local oscillator which displaces a phase of a local oscillating signal by 90° at a high frequency is not required. Also, since the SSB mixer applies the same local oscillating frequency signal to each mixer, the rejection characteristics against undesired signals can be achieved to a level of about 70 dB, experimentally.
摘要:
Single sideband (SSB) mixers and methods of extracting a SSB signal, which are capable of outputting a single frequency using a plurality of mixers and a local oscillating frequency without having to implement phase-shifting. In one embodiment, a single sideband (SSB) mixer comprises a first mixer and a second mixer, wherein the first and second mixers multiply an input IF (intermediate frequency) signal by a local IF signal having the same frequency of the input IF signal; a band-pass filter which passes upper sideband signal output from the first mixer; a third mixer which multiplies the upper sideband signals output from the band-pass filter by a LO (local oscillating) signal; a fourth mixer which multiplies the signals output from the second mixer by the LO signal; and a subtraction device that subtracts output signals of the third mixer from output signals of the fourth mixer. Accordingly, a quadrature local oscillator which displaces a phase of a local oscillating signal by 90° at a high frequency is not required. Also, since the SSB mixer applies the same local oscillating frequency signal to each mixer, the rejection characteristics against undesired signals can be achieved to a level of about 70 dB, experimentally.
摘要:
A method of installing segmental concrete filled tube members. The prefabricated segmental concrete filled tube member has a hollow pipe filled therein with concrete, and a connection flange shaped in a ring radially extending from the peripheries of both ends of the pipe, wherein the segmental concrete filled tube member is integrally connected with another adjacent segmental concrete filled tube member by the connection flange.
摘要:
An apparatus and method for editing transport stream (TS) program information, and a TS recording device using the same, the apparatus including: a demultiplexer that demultiplexes a TS in order to separate the TS into a video stream, an audio stream, and a program information section; a controller that generates new program information using user data obtained from the video stream separated from the TS by the demultiplexer; and a section modifier that modifies the program information section using the new program information generated by the controller. Using the apparatus and method for editing TS program information, the user data can still be used even when the user data is included in a video frame and a recorded program is reproduced at high speed. Thus, controlling the viewing of a program by rating is possible.
摘要:
Provided are methods of fabricating capacitors of semiconductor devices, the methods including: forming a lower electrode on a semiconductor substrate, performing a pre-process operation on the lower electrode for suppressing deterioration of the lower electrode during a process, forming a dielectric layer on the lower electrode using a source gas and an ozone gas, and forming an upper electrode on the dielectric layer, wherein the pre-process operation and the forming of the dielectric layer may be performed in one device capable of atomic layer deposition.
摘要:
A quadrature voltage controlled oscillator includes oscillation circuits for generating in-phase and quadrature-phase oscillation signals that are used to generate in-phase and quadrature-phase output signals. A compensation circuit adjusts biasing in the oscillation circuits depending on a phase relationship between the in-phase and quadrature-phase output signals to automatically control the phase relationship between the oscillation signals.
摘要:
The present invention relates to a catalyst for removing nitrogen oxides from an exhaust gas, a method for preparing the same and a method for removing nitrogen oxide in an exhaust gas using the same, and more particularly, to a catalyst for removing nitrogen oxides from the exhaust gas in which a ceramic fiber carrier is treated by hydrothermal reaction prior to washcoating to improve the hydrothermal stability of catalyst, a method for preparing the same and a method for removing nitrogen oxide in an exhaust gas using the same. The catalyst prepared according to the present invention has excellent hydrothermal stability and an activity of the catalyst remains for a long time. Further, by using this catalyst to remove nitrogen oxides in an exhaust gas, a removal ratio of the nitrogen oxides is greatly enhanced.
摘要:
The present invention relates to a catalyst for removal of nitrogen oxides from exhaust gas, a method of preparing the same and a method of removing nitrogen oxide in an exhaust gas using the same, and more particularly, to a catalyst for removal of nitrogen oxides from exhaust gas in which a ceramic fiber carrier is hydrothermal-treated prior to washcoating to improve the hydrothermal stability of catalyst, a method of preparing the same and a method of removing nitrogen oxide in an exhaust gas using the same.The catalyst prepared according to the present invention has excellent hydrothermal stability and an activity of the catalyst remains for a long time. Further, by using this catalyst to remove nitrogen oxides in an exhaust gas, a removal ratio of the nitrogen oxides is improved more.