Radio-frequency module with phase lock loop and frequency setting
AssigneeFutaba Denshi Kogyo K.K.
InventorsMasahiro Tanaka, Susumu Sakuma
Life of this patent
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Abstract
A radio-frequency module detachably mounted to a transmitter in a radio-control apparatus to supply a high frequency signal to a transmitter. The module includes a phase-lock loop (PLL) circuit along with low pass filters and a voltage controlled oscillator to form a PLL oscillator loop. A rotary switch which is manually set provides an indication to a microprocessor of the desired frequency. The microprocessor supplies the PLL circuit with frequency data. An error voltage is generated by the low pass filters.
Claims3
A radio-frequency module detachably mounted to a transmitter to apply a high-frequency signal to said transmitter, comprising:
- a phase-lock loop (PLL) circuit;
- a microprocessor including a lock detection means and a frequency-setting means;
- said frequency-setting means being capable of setting and controlling by itself a frequency of a carrier wave generated at said PLL circuit;
- said lock-detection means detecting a locked condition of said PLL circuit and generating a lock signal when the locked condition of said PLL circuit is detected;
- a voltage-controlled oscillator;
- at least one low-pass filter applying an output signal indicative of an error voltage to said voltage-controlled oscillator, wherein a cut-off frequency of said at least one low-pass filter is set to a low level when said lock signal is generated;
- and
- a radio-frequency amplifying means for amplifying an output from said voltage-controlled oscillator,
- wherein said radio-frequency amplifying means is activated by a control signal generated from said microprocessor when a predetermined time elapses after the connection between the radio-frequency module and a power source is established.
Dependencies are inferred from the claim text.