摘要:
A radio frequency switch is disclosed. The switch includes a plurality of first substrates in which a ground surface is formed on each of the first substrates and a micro-strip line and a semiconductor on/off switch are disposed on a plane surface of the ground surface, a plurality of second substrates in which a ground surface is formed on each of the second substrates and a micro-strip line is disposed on a plan surface of the ground surface, the second substrates being combined with the first substrates so as to cross each other and being electrically connected to the first substrates, and combining means for combining the first and second substrates so as to cross each other.
摘要:
A wideband monopole antenna assembly includes a substrate having an antenna connector, a wideband monopole antenna positioned on the substrate, and a feeder unit positioned on the rear surface of the substrate for supporting the antenna with a part thereof bent at a predetermined angle. The wideband monopole antenna has a feeder portion shorter than conventional antennas for compactness of the antenna.
摘要:
A wideband monopole antenna assembly includes a substrate having an antenna connector, a wideband monopole antenna positioned on the substrate, and a feeder unit positioned on the rear surface of the substrate for supporting the antenna with a part thereof bent at a predetermined angle. The wideband monopole antenna has a feeder portion shorter than conventional antennas for compactness of the antenna.
摘要:
Disclosed is a return-to-zero (RZ) optical transmission device. A light source outputs a carrier wave. A precoder encodes an inputted non-return-to-zero (NRZ) electrical signal. A delay element delays the encoded signal. A Mach-Zehnder interferometer modulator has two electrodes. The Mach-Zehnder interferometer modulator configured to modulate phase and intensity of the carrier wave using respective output signals of the precoder the delay element applied, and output an RZ optical signal.
摘要:
A duobinary optical transmission apparatus is provided to generate duobinary optical signals, without using an electric low-pass-filter (LPF), by restricting a bandwidth of a Mach-Zehnder-interferometer-type optical intensity modulator (MZ MOD). Alternatively, a LPF having a single pole with a single capacitor is implemented instead of an expensive LPF, thereby providing a simple transmitter with a lower production cost in comparison with a transmitter using a conventional electric LPF.
摘要:
Disclosed is a broadband log-periodic dipole antenna, which has first and second radiating elements alternately and symmetrically arranged in both surfaces of a dielectric substrate according to the corresponding PCS frequency band, IMT-2000 frequency band, and wireless LAN (IEEE 802, 11a/b) frequency band, so that the first and second radiating elements are alternately supplied with signals to make the impedance matching, thereby producing high gain in each of the resonant frequency bands and preventing the distortion of the radiating patterns owing to the broadband characteristics. The arrangement of the first and second radiating elements in both surfaces of the dielectric substrate considerably also reduces the size of the antenna, thereby facilitating mass production with low cost.
摘要:
A wireless remote access base station for converting a downstream optical signal to a downstream radio frequency (RF) signal, transmitting the converted downstream RF signal wirelessly, converting a received upstream RF signal to an upstream optical signal, and transmitting the upstream optical signal is provided. The remote base station includes: an electro-absorption modulator (EAM) for converting a downstream optical signal to a downstream RF signal and an upstream RF signal to an upstream optical signal; an antenna for transmitting the downstream RF signal wirelessly and outputting the upstream RF signal received wirelessly to the EAM; and an amplifier, which is located between the EAM and the antenna, amplifies the downstream RF signal and outputs the amplified downstream RF signal to the antenna.
摘要:
A wireless remote access base station for converting a downstream optical signal to a downstream radio frequency (RF) signal, transmitting the converted downstream RF signal wirelessly, converting a received upstream RF signal to an upstream optical signal, and transmitting the upstream optical signal is provided. The remote base station includes: an electro-absorption modulator (EAM) for converting a downstream optical signal to a downstream RF signal and an upstream RF signal to an upstream optical signal; an antenna for transmitting the downstream RF signal wirelessly and outputting the upstream RF signal received wirelessly to the EAM; and an amplifier, which is located between the EAM and the antenna, amplifies the downstream RF signal and outputs the amplified downstream RF signal to the antenna.
摘要:
Disclosed is a duobinary optical transmitter, which includes a laser source for outputting light with a predetermined wavelength; a Mach-Zehnder interferometer-type optical intensity modulator for modulating the intensity of the light according to a three-level data signal inputted through a modulation terminal; a low-pass filter for converting an inputted two-level binary data signal into a three-level data signal through an interference among codes; and, a modulator driver/amplifier for amplifying the three-level data signal and then outputting it to the modulation terminal, wherein the overall bandwidth of the low-pass filter, the modulator driver/amplifier, and the optical intensity modulator corresponds to approximately ¼ of the clock frequency of the two-level binary data signal.