Abstract: The present invention discloses a bandpass amplifier having gain and bandpass performance. The bandpass amplifier includes an input match unit for matching the gain of the amplifier and having a first filter response; a first bias unit electrically connected to the input match unit for driving the first terminal of the amplifier and having a first high pass filter response; a gain stage electrically connected to the first bias unit for providing the flat gain of the amplifier; a second bias unit electrically connected to the gain stage for driving the second terminal of the amplifier and having a second high pass filter response; and an output match unit electrically connected to the second bias unit for matching the gain of the amplifier and having a second filter response.

Abstract: The present invention discloses a gain amplifier, capable of concurrently operating at three different frequency bands. The gain amplifier comprises an amplification stage for amplifying a signal applied to an input of the amplifier and a triple-band resonance load connected between a DC bias voltage and a DC bias input of the amplification stage. The triple-band resonance load uses a set of reactive elements to provide match in a first frequency band, a second frequency band and in a third frequency band, such as at 2.4 GHz, 5.8 GHz and 9.0 GHz. According to the gain amplifier of the present invention, it can effectively provide triple-band signal amplification and in-band interference suppression for various multi-standard coexist communication systems.

Abstract: The present invention discloses a gain amplifier, capable of concurrently operating at three different frequency bands. The gain amplifier comprises an amplification stage for amplifying a signal applied to an input of the amplifier and a triple-band resonance load connected between a DC bias voltage and a DC bias input of the amplification stage. The triple-band resonance load uses a set of reactive elements to provide match in a first frequency band, a second frequency band and in a third frequency band, such as at 2.4 GHz, 5.8 GHz and 9.0 GHz. According to the gain amplifier of the present invention, it can effectively provide triple-band signal amplification and in-band interference suppression for various multi-standard coexist communication systems.

Abstract: The present invention discloses a dual-band RF transceiver. The transceiver comprises a first module, used as the RF front-end of the dual-band transceiver and used for receiving and transmitting a first RF signal and a second RF signal; a second module, electrically connected to the first module, used as the IF IQ modulator/demodulator of the dual-band RF transceiver; a third module, electrically connected to the first and the second modules, used as the tripe-band phase-locked frequency synthesizer of the dual-band RF transceiver and used for providing a first local oscillating signal and a second local oscillating signal to the first module, and a third local oscillating signal to the second module. The dual-band RF transceiver according to the present invention realizes the dual-band triple-mode operation of IEEE802.11 a/b/g by a single dual-band RF module, and therefore the circuit size, power dissipation, component count, and cost can be dramatically reduced.

Abstract: A dual-band bandpass filter with stepped-impedance resonators uses only one circuit to generate dual-band effect. It adopts the principle of stepped-impedance resonator, which contains a connecting section and two coupling sections. The impedance and electrical length of the connecting section and coupling sections conforms to a selected condition to generate two passbands at desired frequencies. A multi-layer broadside-coupled parallel lines structure may be applied to increase coupling-amount between the parallel lines so that the dual-band bandpass filters have broader bandwidth and less loss.

Abstract: A dual-band bandpass filter with stepped-impedance resonators uses only one circuit to generate dual-band effect. It adopts the principle of stepped-impedance resonator, which contains a connecting section and two coupling sections. The impedance and electrical length of the connecting section and coupling sections conforms to a selected condition to generate two passbands at desired frequencies. A multi-layer broadside-coupled parallel lines structure may be applied to increase coupling-amount between the parallel lines so that the dual-band bandpass filters have broader bandwidth and less loss.

Abstract: The present invention discloses a filter using multilayer ceramic technology. The filter comprises an input port, an output port, a first lumped resonator and a first step-impedance resonator connected to the input port, a second lumped resonator and a second step-impedance resonator connected to the output port, a coupling capacitor used for the coupling of the first lumped resonator and the first step-impedance resonator to the second lumped resonator and the second step-impedance resonator. The filter according to the present invention can provide the multi-transmission zeros in the stopband to isolate the adjacent channel and suppress the harmonics, and provide the transmission poles in the passband to have lower insertion loss. In addition, a manufacturing method for the filter using multilayer ceramic technology is also disclosed.

Abstract: A spurline directional coupler includes a first coupling section and a second coupling section that are in parallel with each other for coupling, and a first sub-coupling section and a second sub-coupling section coupled with the first coupling section, and a third sub-coupling section and a fourth sub-coupling section coupled with the second coupling section. The parallel coupling relationship between the coupling section and the sub-coupling sections generates a capacitive effect thereby may improve isolation and directivity of the spurline directional coupler.

Abstract: The present invention discloses a filter using multilayer ceramic technology. The filter comprises an input port, an output port, a first lumped resonator and a first step-impedance resonator connected to the input port, a second lumped resonator and a second step-impedance resonator connected to the output port, a coupling capacitor used for the coupling of the first lumped resonator and the first step-impedance resonator to the second lumped resonator and the second step-impedance resonator. The filter according to the present invention can provide the multi-transmission zeros in the stopband to isolate the adjacent channel and suppress the harmonics, and provide the transmission poles in the passband to have lower insertion loss. In addition, a manufacturing method for the filter using multilayer ceramic technology is also disclosed.

Abstract: An impedance matching circuit for providing a lossless target signal transmission and rejecting image signals of heterodyne and super-heterodyne transceiver. The impedance matching circuit includes a grounded metal membrane, a first microstrip line connected with an input circuit, a second microstrip line connected with an output circuit, and a third microstrip line connected with either the first microstrip line or the second microstrip line. The first microstrip line is not connected with the second microstrip line, and the length of the third microstrip line is equal to a quarter wavelength of an image signal. When the target signal and the image signal transmit to the impedance matching circuit, the image signal will bypass to a grounded metal membrane, and the target signal will transmit to the output circuit without signal decay through electromagnetic coupling of the first microstrip line and the second microstrip line.

Abstract: A low-phase noise oscillator with a microstrip resonator for generating a target signal with a predetermined frequency is provided. The resonator includes a first microstrip line and a second microstrip line. The first microstrip line is parallel with the second microstrip line without having any contact. A length of the first microstrip line equals a length of the second microstrip line, and the length equals a quarter wavelength of the target signal. When a plurality of oscillating signals is transmitted to the first microstrip line, one of the oscillating signals having the predetermined frequency will be output from the resonator by an electromagnetic coupling generated between the first microstrip line and the second microstrip line.

Abstract: An impedance matching circuit for providing a lossless target signal transmission and rejecting image signals of heterodyne and super-heterodyne transceiver. The impedance matching circuit includes a grounded metal membrane, a first microstrip line connected with an input circuit, a second microstrip line connected with an output circuit, and a third microstrip line connected with either the first microstrip line or the second microstrip line. The first microstrip line is not connected with the second microstrip line, and the length of the third microstrip line is equal to a quarter wavelength of an image signal. When the target signal and the image signal transmit to the impedance matching circuit, the image signal will bypass to a grounded metal membrane, and the target signal will transmit to the output circuit without signal decay through electromagnetic coupling of the first microstrip line and the second microstrip line.

Abstract: A low-phase noise oscillator with a microstrip resonator for generating a target signal with a predetermined frequency is provided. The resonator includes a first microstrip line and a second microstrip line. The first microstrip line is parallel with the second microstrip line without having any contact. A length of the first microstrip line equals a length of the second microstrip line, and the length equals a quarter wavelength of the target signal. When a plurality of oscillating signals is transmitted to the first microstrip line, one of the oscillating signals having the predetermined frequency will be output from the resonator by an electromagnetic coupling generated between the first microstrip line and the second microstrip line.