US 7,095,819 B2 · Direct modulation architecture for amplitude and phase modulated signals in multi-mode signal transmission

Abstract

Multiple-mode direct phase/amplitude modulation circuitry (20) for use in a transceiver (17) of a device such as a wireless handset (10) is disclosed. The modulation circuitry (20) includes a modulation loop (36) for modulating a phase signal into a Gaussian-Minimum-Shift-Keyed (GMSK) signal for transmission in a first mode. The modulation loop (36) may include a phase-locked loop (45) with its frequency controlled by a Σ-Δ demodulation of a compensated version of the phase signal, or alternatively may produce a modulated signal from a direct digital synthesis circuit (70; 70′). An amplitude signal is converted into an analog signal and applied to a single-sideband mixer (43) for combination with a frequency multiplied version of the phase-modulated signal (GMSK(t); PH(t)), producing an amplitude and phase modulated signal for transmission in a second mode.

Claims23

Dependent claims

A multiple-mode amplitude and phase direct modulator circuit, comprising:

a phase modulator leg, comprising:
compensation circuitry for applying delay compensation to an input phase signal;
a modulation loop, for receiving the compensated input phase signal and for producing a phase-modulated output signal as a first mode output signal;
and
a frequency multiplier, coupled to the modulation loop, for multiplying the frequency of the phase-modulated output signal;
an amplitude modulator leg, comprising:
a digital-to-analog converter, for converting an input amplitude digital sequence to an analog amplitude modulated signal;
and
a mixer, having a first input coupled to the frequency multiplier to receive the phase-modulated output signal, having a second input coupled to the digital-to-analog converter to receive the analog amplitude-modulated signal, the mixer for combining the multiplied phase-modulated output signal and the analog amplitude-modulated signal into a second mode output signal.

6 more elements

A wireless telephone device, comprising:

a microphone;
a speaker;
baseband circuitry, coupled to the microphone and speaker, to process audio signals received from and presented to the microphone and speaker, respectively;
polar modulator circuitry coupled to the baseband circuitry, for encoding signals from the baseband circuitry into phase and amplitude digital signals;
transceiver circuitry, comprising:
a phase modulator leg, comprising:
compensation circuitry for applying delay compensation to the phase digital signal;
a modulation loop, for receiving the compensated input phase signal and for producing a phase-modulated output signal as a first mode output signal;
and
a frequency multiplier, coupled to the modulation loop, for multiplying the frequency of the phase-modulated output signal;
an amplitude modulator leg, comprising:
a digital-to-analog converter, for converting the amplitude digital signal to an analog amplitude modulated signal;
and
a mixer, having a first input coupled to the frequency multiplier to receive the phase-modulated output signal, having a second input coupled to the digital-to-analog converter to receive the analog amplitude-modulated signal, the mixer for combining the multiplied phase-modulated output signal and the analog amplitude-modulated signal into a second mode output signal;
and
amplifier circuitry for amplifying the first mode output signal and the second mode output signal, for transmission via an antenna.

13 more elements

Dependencies are inferred from the claim text.

Direct modulation architecture for amplitude and phase modulated signals in multi-mode signal transmission

Life of this patent

Direct modulation architecture for amplitude and phase modulated signals in multi-mode signal transmission

Life of this patent

Abstract

Claims23