Abstract: A low power consumption BPSK modulator uses only one center-tapped transformer and a single-pole double-throw (SPDT) switching arrangement including four field effect transistors and a pair of termination resistors. An advantage of the subject invention is that the DC switching current is reduced by a factor of approximately 1500 with respect to a conventional diode ring modulator. An extremely important advantage of the subject invention in the field of handheld battery-powered communications equipment is that the subject apparatus can be made relatively small due to the necessity for only one transformer.

Abstract: A low power consumption BPSK modulator uses only a single input transformer which is not required to be center-tapped, and a switching arrangement including four junction field effect transistors. An advantage of the subject invention is that the DC switching current is reduced by a factor of approximately 1500 with respect to a conventional diode ring modulator. The carrier signal loss of the subject apparatus is lower than that exhibited by a ring modulator due to the use of only a single transformer, and due to the low on-resistance of the JFETs. An extremely important advantage of the subject invention in the field of cordless telephone handsets is that the subject apparatus can be made relatively small due to the necessity for only one transformer.

Abstract: A data transmission system includes a source of a data signal and a modulator, responsive to the data signal, producing a first modulated signal representing the data signal and a second modulated signal representing a signal 180 out-of-phase with the data signal. The first and second modulated signals are transported via a transmission channel. A first demodulator demodulates the transported first modulated signal and a second demodulator demodulates the transported second modulated signal. A subtractor, responsive to the first and second demodulators, produces a signal representative of the data signal.