Amplifiers – Having light-controlled or activated device
Patent
1987-10-29
1989-05-23
Mullins, James B.
Amplifiers
Having light-controlled or activated device
330109, 330294, 330305, 330308, 455340, H03F 3189
Patent
active
048334197
ABSTRACT:
A radio circuit apparatus for broadcast frequencies promotes micro miniaturization and avoids the production of unwanted radiation by incorporating tunable R-C circuits in place of inductive elements. The apparatus provides simultaneous tuning of RF, mixer, and local oscillator circuits by coupling variable radiation levels to a plurality of radiation-sensitive resistor elements in each circuit. In one configuration of the tuner portion, a rod having a radioactive coating is mounted coaxially within a cylindrical parallel array of resistor elements, the elements being connected in tunable Wien-bridge and/or twin-T circuits. An axially movable, cylindrical shutter is interposed between the rod and the resistor elements for variably blocking the radiation from the rod for tuning the circuits. In another configuration, a conductive plate is formed on the shutter for capacitive coupling to other plates placed in association with the resistor elements, the plates forming a pair of variable capacitors in a Wein-bridge circuit, the combination of variable resistors and capacitors compounding to extend the tuning range of the circuit. In another configuration, a variable voltage is coupled individually to an array of field-effect transistors that serve as the variable resistance elements. In a further configuration, a variably illuminated optical conduit is positioned adjacent to a plurality of photo-resistor elements, each element receiving a portion of light from the conduit. The apparatus can be configured as a transmitter as well as for reception.
REFERENCES:
patent: 3566291 (1971-02-01), Tice, Jr.
Barditch, "Adapting Conventional VHF Equipment to Molecular Electronics", Electronic Design, Feb. 17, 1964, pp. 44-51.
LandOfFree
Non-inductive radio apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Non-inductive radio apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-inductive radio apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1732891