Industrial Technology Research Institute

Ting-Yuan Cheng

Keng-Li Su

Yung-Hue Chen

An upconverter for mixing a single-ended RF signal with a differential local oscillator signal to generate a differential IF signal, that includes a source degenerated first differential pair comprising matched first and second transistors, each having source, gate and drain terminals, wherein the gate of the first transistor receives the input signal and the gate of the second transistor receives a ground potential, and a second differential pair comprising matched third and fourth transistors, each having source, gate and drain terminals, and a third differential pair comprising matched fifth and sixth transistors, each having source, gate and drain terminals, wherein the sources of the third and fourth transistors are coupled to the drain of the first transistor and the sources of the fifth and sixth transistors are coupled to the drain of the second transistor, the gate of the third transistor is coupled to the gate of the fifth transistor and the gate of the fourth transistor is coupled to the gate of the sixth transistor, the drain of the third transistor is coupled to the drain of the sixth transistor and the drain of the fourth transistor is coupled to the drain of the fifth transistor, the gates of the third and fourth transistors receive the differential local oscillator signal, the drains of the third and fourth transistors supply the differential IF signal, the gate of the first transistor is coupled to the single-ended RF signal, and the gate of the second transistor is coupled to a DC control signal.

Broadband single-ended input upconverter

The present invention pertains to a frequency-lock filtering receiver and the method for the same. The receiver enters a tuning mode before receiving signals. A frequency synthesizer then generates the radio frequency (RF) to be received and adjusts the central frequency of a tunable filter through feedback control so as to lock in the RF to be received. Afterwards, the receiver enters a receiving mode to receive RF signals using an antenna and uses the central frequency of the tunable filter locked in the tuning mode to filter the RF signals and to receive signals.

Frequency-lock filtering receiver

The analog phase frequency detecting apparatus includes the devices described below. The first frequency sensitive device is used to amplify a first input signal with a gain function, which changes responding to the frequency of the reference input signal. The transfer characteristic curve of the first frequency sensitive device includes a monotonous decrease (or increase) curve. The second frequency sensitive device is utilized to amplify an oscillating signal with the varying gain function responding to the frequency of the oscillating signal. The first and the second DC component extracting device is used to extract the direct current component of the first and the second amplified input signal. The comparing device is used to generate a frequency locking signal, in addition, the phase detecting device generates a phase locking signal when the phase of the reference input signal is equal to that of the oscillating signal. The loop filter generates a voltage level responding to the frequency locking signal and the phase locking signal. Then the voltage controlled oscillator generates the output signal that has the same frequency and constant phase relationship as that of the reference input signal responding to the frequency locking signal and the phase locking signal.

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Hsinchu, Taiwan

Ting-Yuan Cheng