Abstract: A power amplifier includes a first transformer, a first transistor, a first resistor, a second transformer, a second transistor, a second resistor, and a bias circuit. The first transformer drives the first transistor. The second transformer drives the second transistor. The first transformer is connected in series with the second transformer. The first transistor is connected in series with the second transistor. Therefore, the power amplifier has input impedance and output power both greater than those of a conventional power amplifier.

Abstract: A single-pole-double-throw switch is provided, which is configured to be integrated with a bandpass filtering function and includes four quarter-wavelength transmission lines connected in series, five resonators connected in parallel to each other, and four transistors connected in parallel to four of the five resonators. When two of the four transistors are turned on and the others are turned off, the single-pole-double-throw switch is equivalent to a third-order quarter-wavelength short-circuited stub bandpass filter.

Abstract: The present invention discloses a high-frequency ring coupled Quad comprising at least two transistors, which are cascaded to form a ring and bonded to resonators to form an oscillation source. The open loop feedback gain of the ring coupler of the present invention is higher than that of a conventional cross-coupled pair oscillator because the present invention adopts at least two cascaded transistors. The present invention can solve the problems of low transistor gain and high substrate loss occurring at a high frequency. The present invention has a fully symmetric circuit topology and is free of additional interconnections lines, which can obviously reduce the stray effect of interconnection lines.

Abstract: A traveling-wave switch includes a FET-integrated Coplanar Waveguide (CPW) line structure. The FET-integrated CPW line structure incorporates a transistor, a signal line, and the ground, that can be used to eliminate the limitations imposed by the parasitic inductance of the prior art on the operation frequency of the switch. The signal line is connected directly to the drain of the transistor, eliminating the parasitic inductance caused by the connection wire between the signal line and the transistor. The source of the transistor is coupled directly to the ground of the coplanar waveguide line, thus eliminating the parasitic inductance between the transistor and ground, and raising the operation frequency of the switch.

Abstract: A unilateral feedback power amplifier utilizes new feedback techniques and devices to make the amplified high-frequency signal unilateral, let the output power, power gain and impedance matching simultaneously accomplish the optimal values, and enhance the stability of the system. In this feedback amplifier, a generalized multi-port feedback circuit is in shunt with the input terminal and the output terminal of the power transistor. This generalized multi-port feedback circuit receives an amplified high-frequency signal and eliminates the reverse admittance of the amplified high-frequency signal to let the admittance value of the output amplified high-frequency signal approach zero so as to be unilateral. Moreover, the generalized multi-port feedback power amplifier differs from the conventional power amplifier of cascaded architecture in that the ground terminal of the power transistor is directly connected to the system ground.

Abstract: A unilateral feedback power amplifier utilizes new feedback techniques and devices to make the amplified high-frequency signal unilateral, let the output power, power gain and impedance matching simultaneously accomplish the optimal values, and enhance the stability of the system. In this feedback amplifier, a generalized multi-port feedback circuit is in shunt with the input terminal and the output terminal of the power transistor. This generalized multi-port feedback circuit receives an amplified high-frequency signal and eliminates the reverse admittance of the amplified high-frequency signal to let the admittance value of the output amplified high-frequency signal approach zero so as to be unilateral. Moreover, the generalized multi-port feedback power amplifier differs from the conventional power amplifier of cascaded architecture in that the ground terminal of the power transistor is directly connected to the system ground.

Abstract: A unilateral feedback power amplifier utilizes new feedback techniques and devices to make the amplified high-frequency signal unilateral, let the output power, power gain and impedance matching simultaneously accomplish the optimal values, and enhance the stability of the system. In this feedback amplifier, a generalized multi-port feedback circuit is in shunt with the input terminal and the output terminal of the power transistor. This generalized multi-port feedback circuit receives an amplified high-frequency signal and eliminates the reverse admittance of the amplified high-frequency signal to let the admittance value of the output amplified high-frequency signal approach zero so as to be unilateral. Moreover, the generalized multi-port feedback power amplifier differs from the conventional power amplifier of cascaded architecture in that the ground terminal of the power transistor is directly connected to the system ground.

Abstract: A traveling-wave switch having a FET-integrated Coplanar Waveguide (CPW) line structure. The newly designed FET-integrated CPW line structure incorporating a transistor, a signal line, and the ground, that can be used to eliminate the limitations imposed by the parasitic inductance of the prior art on the operation frequency of the switch. The traveling-wave switch having a FET-integrated CPW line structure can be utilized to effectively raise its operation frequency and reduce its chip size. By reducing the chip size, the new design utilizing the standard GaAs HEMT MMIC process can be used to reduce the production cost of the traveling-wave switch.