Abstract: Disclosed is a construction machine in which a muffler for reducing the noise of exhaust gas emitted from the engine is mounted inside a counterweight.

Abstract: A wireless communication base station sharing apparatus for sharing one antenna between a main system and a subsystem is provided. In the wireless communication base station sharing apparatus, a first signal combiner/distributor is connected to a transmission/reception signal line of a main system duplexer through a first port, distributes a signal received through the first port to second and third ports, combines the signals received through the second and third ports according to the phases of the signals, and provides the combined signal through the first port or a fourth port. A second signal combiner/distributor is connected to a transmission/reception signal line of a subsystem duplexer through a fifth port and the antenna through an eighth port, distributes a signal received through the fifth port to sixth and seventh ports, combines the signals received through the sixth and seventh ports according to the phases of the signals, and provides the combined signal through the fifth or eighth port.

Abstract: A variable radio frequency band filter capable of varying the resonance frequency band comprises a housing having a support; a number of resonator rods arranged along the longitudinal direction of the housing; at least one tuning rod positioned on top of the resonator rods; a tuning support extending through the respective tuning rods along the longitudinal direction of the housing and adapted to slide on top of the respective resonator rods to vary the position of the tuning rods; and a frequency variation unit positioned on a lateral surface of the housing. The frequency variation unit being coupled to an end of the tuning support and adapted to vary the position of the tuning rods, as the tuning support is slid, according to the frequency band.

Abstract: A variable radio frequency band filter capable of varying the resonance frequency band comprises a housing having a support; a number of resonator rods arranged along the longitudinal direction of the housing; at least one tuning rod positioned on top of the resonator rods; a tuning support extending through the respective tuning rods along the longitudinal direction of the housing and adapted to slide on top of the respective resonator rods to vary the position of the tuning rods; and a frequency variation unit positioned on a lateral surface of the housing. The frequency variation unit being coupled to an end of the tuning support and adapted to vary the position of the tuning rods, as the tuning support is slid, according to the frequency band.

Abstract: A variable radio frequency band filter capable of varying the resonance frequency band comprises a housing having a support; a number of resonator rods arranged along the longitudinal direction of the housing; at least one tuning rod positioned on top of the resonator rods; a tuning support extending through the respective tuning rods along the longitudinal direction of the housing and adapted to slide on top of the respective resonator rods to vary the position of the tuning rods; and a frequency variation unit positioned on a lateral surface of the housing. The frequency variation unit being coupled to an end of the tuning support and adapted to vary the position of the tuning rods, as the tuning support is slid, according to the frequency band.

Abstract: A wireless communication base station sharing apparatus for sharing one antenna between a main system and a subsystem is provided. In the wireless communication base station sharing apparatus, a first signal combiner/distributor is connected to a transmission/reception signal line of a main system duplexer through a first port, distributes a signal received through the first port to second and third ports, combines the signals received through the second and third ports according to the phases of the signals, and provides the combined signal through the first port or a fourth port. A second signal combiner/distributor is connected to a transmission/reception signal line of a subsystem duplexer through a fifth port and the antenna through an eighth port, distributes a signal received through the fifth port to sixth and seventh ports, combines the signals received through the sixth and seventh ports according to the phases of the signals, and provides the combined signal through the fifth or eighth port.

Abstract: A variable radio frequency band filter capable of varying the resonance frequency band comprises a housing having a support; a number of resonator rods arranged along the longitudinal direction of the housing; at least one tuning rod positioned on top of the resonator rods; a tuning support extending through the respective tuning rods along the longitudinal direction of the housing and adapted to slide on top of the respective resonator rods to vary the position of the tuning rods; and a frequency variation unit positioned on a lateral surface of the housing. The frequency variation unit being coupled to an end of the tuning support and adapted to vary the position of the tuning rods, as the tuning support is slid, according to the frequency band.

Abstract: A variable radio frequency band filter capable of varying the resonance frequency band comprises a housing having a support; a number of resonator rods arranged along the longitudinal direction of the housing; at least one tuning rod positioned on top of the resonator rods; a tuning support extending through the respective tuning rods along the longitudinal direction of the housing and adapted to slide on top of the respective resonator rods to vary the position of the tuning rods; and a frequency variation unit positioned on a lateral surface of the housing. The frequency variation unit being coupled to an end of the tuning support and adapted to vary the position of the tuning rods, as the tuning support is slid, according to the frequency band.

Abstract: A variable radio frequency band filter capable of varying the resonance frequency band comprises a housing having a support; a number of resonator rods arranged along the longitudinal direction of the housing; at least one tuning rod positioned on top of the resonator rods; a tuning support extending through the respective tuning rods along the longitudinal direction of the housing and adapted to slide on top of the respective resonator rods to vary the position of the tuning rods; and a frequency variation unit positioned on a lateral surface of the housing. The frequency variation unit being coupled to an end of the tuning support and adapted to vary the position of the tuning rods, as the tuning support is slid, according to the frequency band.