摘要:
A filter with which it is possible to control the relationship between a pass band and an attenuation band. In this filter, for example, a single-stage trap filter is electrically connected to a three-stage band pass filter via a coupling capacitor. The trap filter has a serial resonance section composed of a resonator and a resonance capacitor. The serial resonance section is connected in parallel to a capacitive reactance element (capacitor), and a serial circuit composed of an inductive reactance element (inductor) and a PIN diode as a switching element. The capacitive reactance element and the inductive reactance element both serve to make an admittance of the trap circuit substantially zero.
摘要:
An outer conductor, an input terminal electrode, an output terminal electrode, a voltage controllable terminal electrode, and two separated electrodes are formed on the outer face of a dielectric block. Furthermore, on the upper face of the dielectric block, PIN diodes which are voltage controllable reactance elements, and inductors for voltage-controlling the PIN diodes, and a coupling adjustment capacitor are mounted. Frequency shifting capacitors are formed by generation of electrostatic capacitances between the separated electrodes and the inner conductors of the resonance holes, respectively.
摘要:
A frequency variable filter in which both the frequency of an attenuation pole and the attenuation bandwidth can be varied. In the frequency variable filter, two serial resonance sections composed of resonators and resonance capacitors are electrically connected to each other via a capacitor. The respective resonator in each of the serial resonance sections is electrically connected in parallel with a corresponding serial circuit composed of a frequency shifting capacitor and a PIN diode. A coupling capacitor electrically connects the junctions defined respectively between the frequency shifting capacitor and the PIN diode in each of the serial circuits.
摘要:
An antenna-duplexer and communication apparatus in which relative phase distortion of transmitted waves and intrusive waves is low, and which are small-scale. An antenna-duplexer comprises a transmission side circuit, electrically connected between a transmission terminal and an antenna terminal, and a reception side circuit, electrically connected between a reception terminal and the antenna terminal. Two PIN diodes, which are connected in series, are connected only to a resonator of the transmission side circuit which is electrically connected closest to the antenna terminal, and a voltage control terminal is connected to the anodes of the PIN diodes, thereby dividing the high-frequency voltage. One PIN diode is connected to each of the other resonators.
摘要:
In an antenna-sharing device, a transmission filter is electrically connected between a transmission terminal and an antenna terminal, and a reception filter is electrically connected between a reception terminal and the antenna terminal. A signal pattern and a ground electrode are formed on a resonator-mounting surface of a circuit substrate. On the ground electrodes, the resonators constituting the transmission filter are integrally soldered and the resonators constituting the reception filter are integrally soldered. On the mounting surface of the circuit substrate, a transmission filter ground electrode and a reception filter ground electrode are formed. Both ground electrodes are isolated from each other by a gap (slit), and are disconnected from each other.
摘要:
There is disclosed a duplexer comprising: a first external terminal; a second external terminal; an antenna terminal; a first frequency variable filter electrically connected between the first external terminal and the antenna terminal, and composed of at least one resonator and a reactance element electrically connected to the resonator and capable of being voltage-controlled; a second frequency variable filter electrically connected between the second external terminal and the antenna terminal, and composed of at least one resonator and a reactance element electrically connected to the resonator and capable of being voltage-controlled; the predetermined reactance element of the first frequency variable filter being in the on state when the reactance element of the second frequency variable filter is in the on state.
摘要:
A filter assembly includes a transmission filter, a reception filter, a change-over switch, and phase circuits. The transmission filter has first and second ends electrically connected to a first antenna terminal and a transmission terminal, respectively. The reception filter has a first end electrically connected to a second antenna terminal via the change-over switch, and a second end electrically connected to a reception terminal. A main antenna is connected to the first antenna terminal, and a diversity antenna is connected to the second antenna terminal. The change-over switch performs switching control to connect the reception filter to one of the first and second antenna terminals. Thus, the filters utilize a fixed number of resonators regardless of switching control of the change-over switch, thereby achieving optimum filter characteristics.
摘要:
There is provided a frequency-variable-type filter, comprising: a voltage control terminal; at least one resonator; a switching device for being switched on/off by a control voltage supplied to the voltage control terminal; and the switching device being in the off-state, when a control circuit as an external circuit which is electrically connected to the voltage control terminal has high impedance at 0 V.
摘要:
A dielectric filter provided with a dielectric block including at least four resonant through holes that are adjacent to each other. A multipath slot is arranged near three adjacent through holes of the at least four resonant through holes. The multipath slot has an inner conductor formed on an inner surface thereof in order to generate a first capacitance between a first area near the open end of each of the three adjacent through holes and the inner conductor of the multipath slot. A step is formed so that a second capacitance is generated between a second area near the open end of each of two through holes of the at least four resonant through holes and an outer conductor located within the step. An attenuation peak is generated at the lower-frequency side of the passband with the multipath slot and the three adjacent through holes, and an attenuation peak is generated at the higher-frequency side of the passband with the two through holes and the outer conductor within the step.
摘要:
In a band elimination filter, a trap capacitor and a frequency control capacitor are made by using a simple capacitor plate individually provided for each respective resonance circuit.