摘要:
An audio communication system, an audio transmitter and an audio receiver are described herein. In one aspect, the audio transmitter includes: An analog to digital converter configured to convert an analog audio signal into a digital audio signal; a digital compressor configured to compress the dynamic range of said digital audio signal; a digital modulator configured to modulate the compressed digital audio signal into a wireless communication signal; and the analog to digital converter, the digital compressor and the digital modulator are integrated in one integrated circuit. The described devices improve the compression and expansion device linearity, resulting in better match for the compressor at the transmitter and the expandor at the receiver.
摘要:
A method and device for generating an adjustable signal includes a voltage generator configured to continuously adjust an output voltage and output the voltage, a ΣΔ modulator configured to output a digital signal of pre-determined-cycle based on the output voltage and a reference voltage, a counter configured to count the number of a target level in the digital signal of a pre-determined number of cycles, and a digital signal generator configured to generate a target signal based on the number of the target level. The method and device may improve the accuracy of the generated signal while remaining the same feel of continuous adjustment.
摘要:
A circuit for a front-end tunable filter of a communication and broadcast receiver and a tuning method thereof are described herein. In one aspect, the circuit of the tunable filter may be independent of the signal reception link of the receiver. The pre-filter (104) includes a variable capacitance (146) which is adjusted by a tuning signal (160). A negative resistance element (144) and the pre-filter (104) may form an oscillator. The negative resistance element (144) is controlled by an amplitude control signal (162) outputted from an oscillation amplitude control circuit (142). The oscillation amplitude control circuit (142) stabilizes the amplitude of a radio frequency signal (130) in a preset range. An oscillation frequency control circuit (140) stabilizes the frequency of the signal (130) in a preset frequency range by a tuning signal (160). The tuning is completed until both of the amplitude and the frequency of the oscillation signal meet the preset ranges.
摘要:
A circuit for a front-end tunable filter of a communication and broadcast receiver and a tuning method thereof are described herein. In one aspect, the circuit of the tunable filter may be independent of the signal reception link of the receiver. The pre-filter (104) includes a variable capacitance (146) which is adjusted by a tuning signal (160). A negative resistance element (144) and the pre-filter (104) may form an oscillator. The negative resistance element (144) is controlled by an amplitude control signal (162) outputted from an oscillation amplitude control circuit (142). The oscillation amplitude control circuit (142) stabilizes the amplitude of a radio frequency signal (130) in a preset range. An oscillation frequency control circuit (140) stabilizes the frequency of the signal (130) in a preset frequency range by a tuning signal (160). The tuning is completed until both of the amplitude and the frequency of the oscillation signal meet the preset ranges.
摘要:
An adjustable signal generating device and related method for generating the adjustable signal are described herein. The adjustable signal generating device includes: a voltage generator configured to continuously adjust an output voltage and output the voltage; a ΣΔ modulator configured to output a digital signal of pre-determined-cycle based on the output voltage and a reference voltage; a counter configured to count the number of a target level in the digital signal of a pre-determined number of cycles; and a digital signal generator configured to generate a target signal based on the number of the target level. The described method and device improve the accuracy of the generated signal while remaining the same feel of continuous adjustment.