Dual mode portable cellular telephone having switch control of t

Telephonic communications – Having light wave or ultrasonic link for speech or paging... – Including fiber optic link within telephone network

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

455 83, 455 89, 455 331, 455 86, H04Q 732

Patent

active

054229316

ABSTRACT:
A dual mode, portable cellular telephone utilizes an rf switch to control the rf signal path through its rf output stage. A voltage controlled oscillator (VCO) generates an rf signal that is selectively modulated with an fm modulation signal. In an FM modulation mode, the rf signal generated by the VCO is amplified by a first rf amplifier and a second rf amplifier, and then applied to a power amplifier. The power amplifier couples the amplified rf signal to an antenna for broadcasting. A first rf signal path through the rf output stage thus includes the VCO, first rf amplifier, second rf amplifier, and power amplifier, and the resulting rf output signal is FM modulated. In a digital modulation mode, the rf signal generated by the VCO is unmodulated, having a fixed frequency. This is achieved by making the fm modulation signal be a constant signal. The fixed frequency signal is amplified by the first rf amplifier and then applied to a digital modulator as a local oscillator signal. The digital modulator then modulates the local oscillator signal using appropriate modulation signals, and applies the resulting digitally modulated rf signal to the power amplifier. A second rf signal path through the rf output stage thus includes the VCO, first rf amplifier, digital modulator and power amplifier. Control of the rf signal path is achieved by switchably connecting and disconnecting power to the digital modulator and the second rf amplifier.

REFERENCES:
patent: 5276914 (1994-01-01), Ishizuka et al.
patent: 5276917 (1994-01-01), Vanhanen et al.
patent: 5309502 (1994-05-01), Hirai
Fisher, "Dual Mode Mobile Unit for Next Generation Digital Narrow Channel Cellular Telephone System" IEEE 1988.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Dual mode portable cellular telephone having switch control of t does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Dual mode portable cellular telephone having switch control of t, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dual mode portable cellular telephone having switch control of t will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-993158

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.