US 6,480,553 B1 · Gaussian frequency-shift keying transciever for ISM wideband communication

Abstract

A GFSK (Gaussian Frequency Shift Keying) radio transceiver is provided for ISM (Industrial Scientific and Medical) wideband communication. The GFSK radio transceiver includes a transmitter for modulating transmitted signal into RF signal, and a receiver for demodulating received signal into digital form. The transmitter includes a VCO for generating an oscillating signal serving as a carrier signal in the transmitter and a first local oscillating signal in the transmitter; and a variable-gain power amplifier, capable of being adjustable between two gain values, for amplifying the RF signal. The receiver includes a mixer for downconverting the received signal into a first IF signal by using the first local oscillating signal from the transmitter; and an IF demodulator for downconverting the first IF signal into a second IF signal by using a locally generated second local oscillating signal. The GFSK radio transceiver can operate either in half-duplex mode or full-duplex mode in a time-division duplex (TDD) system through micro-processor controls. Further, it utilizes a variable-gain power amplifier that can improve the drawbacks of interference and high power consumption with the prior art, and further utilizes a single wideband VCO to generate an oscillating signal that can be used both as the carrier signal in the transmitter and the first local oscillating signal for the receiver. This allows the GFSK radio transceiver to be implemented with a fewer number of VCOs as compared to the prior art, thus reducing the manufacturing cost.

Claims14

Dependent claims

A GFSK radio transceiver for ISM wideband communication, which comprises:

a transmitter for modulating a data signal into a GFSK RF signal, the transmitter including:
a Gaussian filter;
a VCO for generating an oscillating signal serving as a carrier signal for the transmitted signal, wherein the VCO further includes an oscillation-stage circuit for generating an oscillating signal serving as the carrier signal to modulate the transmitted signal into RF signal;
and a buffer-stage circuit, coupled to the oscillation stage circuit, for buffering the REF signal;
and
a variable-gain power amplifier, which is capable of being adjustable between a low-power gain and a high-power gain, for amplifying the RF signal;
and
a receiver for demodulating received signal into digital form, the receiver including:
a mixer for downconverting the received signal into a first IF signal by mixing the received signal with a first local oscillating signal which is fetched from the oscillating signal from the VCO in the transmitter;
a local oscillator for generating a second local oscillating signal;
an IF demodulator for downconverting the first IF signal from the mixer into a second IF signal by mixing the first IF signal with the second local oscillating signal;
a micro-processor for selecting transceiver operation in half-duplex or full-duplex mode.

9 more elements

A GFSK radio transceiver for ISM wideband communication, which comprises:

a transmitter for modulating transmitted digital signal into RP signal, the transmitter including:
a Gaussian filter for filtering in the transmitted digital signal;
a VCO, receiving the output of the Gaussian filter as input, for generating an oscillating signal serving as carrier signal for the transmitted signal, wherein the VCO includes an oscillation-stage circuit for generating an oscillating signal serving as the carrier signal to modulate the transmitted signal into RF signal;
and a buffer-stage circuit, coupled to the oscillation-stage circuit, for buffering the RF signal;
a PLL circuit, coupled to the VCO, for locking the transmitted signal at a predetermined frequency;
and
a variable-gain power amplifier, which is capable of being adjustable between a low-power gain and a high-power gain, for amplifying the RF signal;
and
a receiver for demodulating received signal into digital form, the receiver including:
an LNA for amplifying received signal prior to being processed by the mixer;
a mixer for downconverting received signal into a first IF signal by mixing received signal with a first local oscillating signal which is fetched from the oscillating signal from the VCO in the transmitter;
a local oscillator for generating a second local oscillating signal;
and
an IF demodulator for downconverting the first IF signal from the mixer into a second IF signal by mixing the first IF signal with the second local oscillating signal.

11 more elements

Dependencies are inferred from the claim text.

Gaussian frequency-shift keying transciever for ISM wideband communication

Life of this patent

Gaussian frequency-shift keying transciever for ISM wideband communication

Life of this patent

Abstract

Claims14