Patent ID: 6452461
Filing Date: 2002-09-17
Classification: H03B,H04L

Abstract:
A high-speed power-efficient coded M-ary FSK modulator comprising:a coding logic, which generates (M/2) Gray code signals in accordance with an (Nâˆ’1) bits control signal, where M=2N, and (M/2) switching oscillators each comprising: a composite crystal resonator with a first end and a second end; a first switch, which is controlled by the Gray code signals, with one end connected to the first end of said composite crystal resonator, and the other end grounded via an equivalent negative resistance circuit; a second switch, which is controlled by serial data, with one end connected to the second end of said composite crystal resonator, and the other end grounded; and a capacitor, with one end connected to the second end of said composite crystal resonator, and the other end grounded; whereby one of said (M/2) switching oscillators is activated by the control signal, and the frequency of the activated oscillator is switched by said serial data for achieving M-ary frequency shift.