Abstract: A phase-locked loop with dual-mode phase/frequency detection is provided. The phase-locked loop circuit includes a dual-mode phase/frequency detector, a loop filter, a voltage-controlled oscillator, and a frequency converter. In addition, the dual-mode phase/frequency detector includes a digital phase/frequency detector, an analog phase/frequency detector, a charge pump, and a control unit. When the phase-locked loop circuit starts, the control unit causes a detection output signal from the dual-mode phase/frequency detector to correspond to a digital signal from the digital phase/frequency detector. When the phase-locked loop circuit approaches a lock state, the control unit causes the detection output signal to correspond to an analog signal from the analog phase/frequency detector. The phase-locked loop with dual-mode phase/frequency detection has the advantages of providing linear characteristics, fast switching speed, and high sensitivity.

Abstract: A phase-locked loop with dual-mode phase/frequency detection is provided. The phase-locked loop circuit includes a dual-mode phase/frequency detector, a loop filter, a voltage-controlled oscillator, and a frequency converter. In addition, the dual-mode phase/frequency detector includes a digital phase/frequency detector, an analog phase/frequency detector, a charge pump, and a control unit. When the phase-locked loop circuit starts, the control unit causes a detection output signal from the dual-mode phase/frequency detector to correspond to a digital signal from the digital phase/frequency detector. When the phase-locked loop circuit approaches a lock state, the control unit causes the detection output signal to correspond to an analog signal from the analog phase/frequency detector. The phase-locked loop with dual-mode phase/frequency detection has the advantages of providing linear characteristics, fast switching speed, and high sensitivity.

Abstract: A RF power amplifier with the advantages of high output efficiency and a wide range of gain control is disclosed. By appropriately biasing the power transistor of the power-stage amplifier in the RF power amplifier, the power-stage amplifier functions as a class C amplifier. By varying the bias source of the driving-stage amplifier and keeping the bias sources of the input-stage and power-stage amplifiers at a fixed level, the driving-stage can output a driving signal with a wide range of variable gain. Consequently, the driving signal can be used to drive the power-stage amplifier to obtain highly efficient output and of a wide range of output power gain control.

Abstract: This invention discloses a monolithic microwave integrated circuit (MMIC) package with filtering property. The filtering action is inherent with the structure of the package. This structure overcomes the limitation of traditional packages, which can only transmit the signal without processing the signal. A specially designed surface-mountable structure is used in the input and the output terminals. Any impedance from this special structure can be compensated by the filtering structure in each port. The filtering structure is located between the input (or the output) structure and the die cavity in each port. The package also provides ground connection to the MMIC by means of metal-filled via holes connected to the surface mounting side.