AM/FM time division surface wave device transmitter
AssigneeTexas Instruments Incorporated
InventorsJerry L. Norris, Clinton S. Hartmann
Life of this patent
Estimating the term…
Abstract
A device for sample modulating electronic information signals which includes mixing circuitry having a first input coupled to receive information signals, a second input for receiving electrical sampling signals, and an output for generating thereon electrical output signals proportional to the product of the information signals and the sampling signals. Also included is an acoustic surface wave device having an impulse response of predetermined shape and finite length. The surface wave device has an output coupled to the second input of the mixing circuit for generating thereon the sampling signals. These signals are proportional to the finite impulse response of predetermined shape, and accordingly have a highly controllable frequency spectrum.
Claims18
A time division sample modulating device for sample modulating electronic information signals comprising:
- signal modulator means for receiving input signals a(t) in the audio range and generating information signals i(t) having a bandwidth substantially larger than the bandwidth of the audio range input signals a(t);
- electronic signal shaping means having an impulse response h(t) of a predetermined shape and a finite length for receiving input impulse signals p(t) and generating sampling signals p(t) *h(t) as the convolution of the input impulse signals p(t) with the impulse response h(t) thereof;
- and
- mixing means having first and second inputs respectively connected to the outputs of said signal modulator means and said electronic signal shaping means for receiving said information signals i(t) and said sampling signals p(t) *h(t) therefrom and generating electrical output signals proportional to the product of said information signals i(t) and said sampling signals p(t) *h(t).
A cordless communication system comprising:
- a base unit;
- at least one portable unit;
- and
- each of said base unit and said portable unit having time division transmitter means for transmitting to each other via electromagnetic radiation in one finite frequency band during different time intervals samples of information signals;
- said time division transmitter means of each of said base unit and said portable unit including
- signal modulator means for receiving input signals a(t) in the audio range and generating information signals i(t) having a bandwidth substantially larger than the bandwidth of the audio range input signals a(t),
- electronic signal shaping means having an impulse response h(t) of a predetermined shape and a finite length for receiving input impulse signals p(t) and generating sampling signals p(t) *h(t) as the convolution of the input impulse signals p(t) with the impulse response h(t) thereof, and
- mixing means having first and second inputs respectively connected to the outputs of said signal modulator means and said electronic signal shaping means for receiving said information signals i(t) and said sampling signals p(t) *h(t) therefrom and generating electrical output signals proportional to the product of said information signals i(t) and said sampling signals p(t) *h(t).
Dependencies are inferred from the claim text.