JPS5980016A - Receiver of frequency synthesizer - Google Patents

Abstract

PURPOSE:To ensure the perfect automatic sweep tuning, by turning off a mute signal to turn on a tuning indicator only when the perfect tuning is obtained after having extremely sharp synchronous wave detection characteristics for the synchronous wave detection signal of a synthesizer control circuit. CONSTITUTION:A synchronous wave detecting circuit provided inside a synthesizer control circuit 12' gives synchronous wave detection to the IF supplied from an IF amplifier 4, and this wave detection output signal is used as a sweep stop signal. In this case, the synchronous wave detection characteristics are extremely sharp. While a mute signal is delivered from an output port P2 of the circuit 12' during a sweep period to open switch circuits 6 and 18. Therefore no demodulation output nor tuning indication output are delivered at all, and the mute signal is cut off only when the perfect tuning is obtained. Then a tuning indicator 10 is turned on. Furthermore the automatic sweeping is never stopped at the areas other than a desired frequency since the sweep stop control is carried out with synchronous wave detection.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a frequency synthesis receiver, and more particularly to a receiver tuning instruction mechanism.

Figure 1 shows the conventionally commonly used frequency SYN1! I.J.
Iza receiver (1 block diagram showing an example of 8 aircraft, consisting of a part of the receiver and a control section.In the corner section, the power is supplied from an antenna (not shown) to the antenna input terminal 1. ) is selected by the antenna tuning circuit 2 and supplied to the C mixer 3. In the mixer 3, it is mixed with the local oscillation signal supplied from the local oscillator 8, thereby combining both signals. For the frequency of
The signal is converted into a sum and difference signal and supplied to the intermediate frequency amplifier 4. The intermediate frequency amplifier 4 has a built-in IF filter, and extracts and amplifies only the intermediate frequency signal IF of a predetermined constant frequency from the signal supplied from the mixer 3, and then sends it to the detection circuit. supplied to The detection circuit 5 extracts a demodulated signal from the intermediate frequency signal I[-, also known as CJ, and this demodulated signal is supplied from the synthesizer circuit 12 to be described later.
The signal is supplied to the -C output terminal 7 via a switch circuit 6 which is opened and closed depending on the lucky number. In addition, a part of the intermediate frequency signal "■" extracted by the intermediate frequency amplifier 4 is converted into a 41η signal (s"PC) by a 7.r router for tuning instruction having narrow band characteristics and a rectifier amplifier circuit. is supplied to the tuning instruction circuit 9 having the characteristics shown in FIG. 2, and a signal corresponding to one level of the tuning signal is extracted.The output signal 2-; 10 to display the tuning status.

On the other hand, the synthesizer 1 noise control circuit 12 includes a frequency divider that divides the local valve 1 frequency supplied from the local oscillator 8, a reference frequency generator for comparison, and a phase! It has a comparator that compares the divided output of the local oscillation frequency and the output signal of the reference frequency generator for comparison, and extracts a signal proportional to the ()''l phase difference at -. 1- after the ripple component is removed in the path noise loop 11, the signal is supplied to the antenna tuning circuit 2J3 and the local oscillator 8 (well-known)
- Zlotzklub is created lj4. :1:1. −、、
This Shint? The riser control circuit 12 has a reception frequency lIl.
The signal is displayed on the frequency display 13, and the reception mode and reception frequency are controlled according to the output signal of the toe board 14. Furthermore, this signal riser control circuit 12 determines the reception state by taking in the output signal of the frequency display 9 via the port P1 (), and when operating the keyboard 14 marked +'+rt and before) the phase [1 During a transient state of the loop, signals are sent from the baud 1 to P2 to the mini 1 to 1 to open the switch circuit 6, thereby preventing unnecessary OUT) J signals from being sent. In addition, if automatic tuning is instructed to the automatic tuning control circuit 12 connected to the keyboard 14, the output level of the tuning instruction circuit 9 supplied to the input capacitor hP1 exceeds a predetermined level. Sometimes synchronization was obtained - (synchronization) Stop the ω pull.

However, in the receiver with the above configuration (,t,
If the interval between the 1, 1, and 1 subtraction frequencies determined by the synchronization control circuit is narrow, for example, 1 kHz, and the receiving power level is high, the tuning indicator will light up before and after the desired frequency. t-)-S:1-Yang mode has a problem in that +M pull stops at an undesired frequency.

An object of the present invention is to provide a frequency synthesizer receiver in which the tuning indicator is turned on and the sweep operation is stopped only when the desired frequency is reached.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The frequency synchronization receiver according to the present invention will be described in detail below with reference to the drawings.

Figure 3 shows this l? FIG. 1 is a circuit diagram showing an embodiment of a frequency synthesizer receiver according to Ikei, and the same parts as in FIG. In the figure, reference numeral 9' denotes a tuning instruction circuit which uses a part of the intermediate frequency signal IF output from the intermediate frequency amplifier 4 as a panograph, and there is no narrow band filter installed inside it; Only the function of rectifying and amplifying the frequency signal 1F is provided, and its output signal is supplied to the tuning indicator 10 via a switch circuit 18 which is audible by the Micoult signal g.

Reference numeral 12' is shown in FIG. 1, and the IJ control circuit 12 has a built-in synchronous detector and is supplied from the intermediate frequency amplifier 4 to the input port P3. Performs synchronous detection of intermediate frequency signals.

In the receiver configured in this manner, a synchronous detection circuit installed inside the control circuit 12- of the synthesizer 1J and 9 synchronously detects the intermediate frequency signal IF supplied from the intermediate frequency amplifier 4, This detection output signal is used as the sweep stop 1- signal. The characteristics of this synchronous detection circuit are, for example, intermediate frequency signal I F (4!i0 K H
z) 2 and ±600 Hz, making it extremely terra 11-pui. Therefore, in the case of 1-skin↑・-on, there will be no malfunction even if there is a sweep interval of, for example, IKHz, and the sweep will be stopped only when it is completely tuned to the desired frequency. Also, during the sweep period, the output port P of the synthesizer control circuit 12-
The mute signal J is opened to the switch circuit 6.18. Therefore, during the sweep, the demodulation output and the synchronization instruction output are not sent out at all.At point 11.1, when complete synchronization is achieved, the mute signal is cut off, and the demodulation output is sent out and the tuning indicator 10 lights up. I hope that the display will be displayed, and when there is a strong electric field, there will be a
The problem of erroneous lighting of the C tuning indicator 10 can be reliably prevented. j, Since the sweep stop control by synchronous detection is f5, its characteristics are different from those of other people)
Even with respect to the level, the automatic sweep will not be stopped erroneously at a portion outside the desired frequency by one meter.

As will be explained below, according to the present invention (a high-frequency receiver), it is possible to completely tune to a strong electric field 11.
Problem where the synchronization display is incorrectly displayed in the front and rear parts of Qi (
13 and 13) This has an excellent effect of preventing the problem that the J sweep stops at frequencies other than the desired frequency.

[Brief explanation of drawings]

Figure 1 (,L Conventional frequency syntax
Fig. 2 is a characteristic diagram of the 111 tone instruction circuit shown in Fig. 1, Fig. 33 is a circuit diagram showing the 111th tone indicating circuit shown in Fig.
, 1 wave failure signal 1 (reception)) There is a circuit diagram according to the embodiment.
Ie combiner, 4... intermediate frequency amplifier, 5... detector,
6. lft...Sue r! Di circuit, 8...Local oscillator, 9'...Lv4 instruction circuit, 10...61.
11h indicator, 11... filter, 12-... synt
1 Noise control 211 circuit, 13... Frequency display, 14... Keychain, 1 Figure 1, Figure 2, Figure 7;] (V) Te (KHzl Figure 3)

Claims (1)

[Claims] In a frequency synthesis p-1 noise receiver that uses the automatic sweep function, use the synchronous detection output to stop the automatic sweep.
When the desired frequency is received, the tuning instruction signal supplied to the tuning indicator, which operates according to the receiving input level, is cut off due to the mute signal generated when the Tsukloop or overflow condition occurs. It is characterized by the fact that the force automatic sweep is stopped (9) and the frequency synchronization of the tuning indicator is prevented.
lit.