JPS5910612B2 - synthesizer receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthesizer receiver in which a local oscillation circuit is constructed of a PLL synthesizer, and which selects a channel by changing the channel selection step by automatic sweep and manual sweep.

In general, a PLL synthesizer is configured as shown in FIG.
It stably generates an oscillation frequency fo that is N times higher than the reference frequency fr.In the radio receiver, the oscillation frequency fO of the voltage-controlled oscillator 2 is used as a local oscillation frequency, and the reference frequency fr is used as the inter-office frequency of the receiving band. By setting
The local oscillation frequency is obtained by inter-office frequency steps.

By the way, inter-office frequencies may differ depending on the region.

For example, in the FM band, the interstation frequency is generally 1 0 0
It is set at KHz intervals, but in Europe there are stations with frequencies of 50 KHz or fractions of 10 KHz, and the reference frequency fr is 100 K}lz
5 0 K}iz or 10K
Stations with fractions of Hz are unreceivable.

Therefore, if the reference frequency fr is set to 10 K}lz, all stations can be received, but in this case, the PLL is locked every 10 KHz, which increases the sweep time during automatic sweep, which is not preferable. .

Therefore, a method as shown in FIG. 2 can be considered as a method of shortening the sweep time in automatic sweep and receiving all stations.

That is, the reference frequency fr is set to 10 KHz, and by counting the sweep pulses from the sweep pulse generation circuit 4, the number of input pulses to the sweep power converter 5 that changes the frequency division ratio N of the programmable frequency divider 1 is determined. is changed by automatic sweep and manual sweep.During automatic sweep, 10 pulses are generated at a time as shown in Figure 4b to increase the sweep force.
In other words, by changing the frequency division ratio N by 10,
By changing the oscillation frequency of the voltage controlled oscillator 2 in increments of 100 KHz, the oscillation frequency of the voltage controlled oscillator 2 is changed in increments of 100 KHz, and during manual sweeping, one pulse is generated as shown in FIG. By changing the frequency, the oscillation frequency fo is changed every 10 KHz, and by changing the channel selection step, the sweep time in automatic sweep can be shortened, and all stations can be received by manual sweep.

However, in this case, if you switch to automatic sweep from a state in which you are tuned to a station with a normal inter-office frequency using manual sweep, reception may become impossible.

For example, suppose you are tuning to and receiving 9 0.1 5 ME1z with manual sweep, and if you switch to automatic sweep, the PLL
is always locked to a value deviated by 50 KHz from the regular inter-station frequency arrangement, such as 9 0.2 5, 9 0.3 5, etc. If a station happens to exist there, the sweep will stop and reception will begin, but generally Many people do not receive it.

Therefore, the present invention has been made in view of this point, and an object thereof is to provide a synthesizer receiver that can automatically sweep stations with a regular inter-station frequency arrangement when switching from manual sweep to automatic sweep.

An embodiment of the present invention will be described below with reference to FIG.

Functional parts that are the same as those in Figures 1 and 2 are indicated by the same figure numbers.

4 generates ten sweep pulses each when the automatic sweep key 6 is operated, as shown in FIG. 4b, and when the manual sweep key 7 is operated.
5 is a sweep pulse generating circuit which generates one pulse as shown in FIG.
This is a sweep power counter/counter that counts the sweep pulses of ing.

8 is also composed of decimal counters A', B', C', and is driven by the sweep pulse from the sweep pulse generating circuit 4 and the carry signal CA from the first stage counter A of the sweep force counter 5. AN to input the sweep pulse by operating the automatic sweep key 6 with the auxiliary power output
It is connected to the sweep pulse generation circuit 4 via the D gate 9, and is connected to the AND gate so as to drive the second and subsequent stages when the manual sweep key 7 is operated and there is a carry signal CA from the sweep force counter 5. 10 and an OR gate 11 are connected.

Further, when the automatic sweep key 6 is operated, the numerical value of the auxiliary counter 8 is connected to the sweep force counter 5 so that it is preset by the generation of the preset enable signal PE.

Incidentally, when the power is turned on, the same numerical value, for example, a numerical value corresponding to the lowest reception frequency, is set in the sweep force counter 5 and the auxiliary counter 8 by a means (not shown).

Therefore, during automatic sweep, the sweep force counter 5 and the auxiliary counter 8 change by the same value, but during manual sweep, the auxiliary counter 8 is driven by the carry signal CA of the sweep force counter 5, so the values of both counters 5 and 8 are not necessarily the same. They will not be the same.

Next, the operation of the present invention having such a configuration will be explained.

First, it is assumed that a station of 90.0 MHz is currently being received.

The local oscillation frequency fo required at this time is the intermediate frequency 1
0-7ME1z, lower heterodie 7 system, it becomes 79-3 MHz, and since the PLL reference frequency fr is set to 10 KHz, the frequency division ratio N required for the programmable frequency divider 1 is II 7ci 3
o I+, and the sweep force counter 5 is I+ 793o
Fixed to I+.

At this time, the auxiliary counter 8 is also "7 9 3 0"
” is set.

When the automatic sweep key 6 is operated in this state, 10 pulses are input to the sweep force counter 5 and the auxiliary counter 8, resulting in II 79 4 0 1+, and the voltage controlled oscillator 2 outputs a local oscillation frequency of 7 9. 4 MHz is generated and a tuning operation of 9 0.1 MHz is performed.

When the reception signal S is generated, the sweep pulse generation is stopped, the sweep power output 5 is fixed at "7940", and a station of 90.1 MHz is received.

However, if the received signal S is not generated, 9 0.2,
90.3, 90.4 MHz, etc. are swept at 100 KHz intervals until the received signal S is generated.

During this time, 10 pulses are input to the auxiliary counter 8, so that it is changing at the same value as the sweep force counter 5, and it is assumed that the same < 9 0.0 MEiz is being received, and the manual sweep key 7 is operated. Manual sweep will be explained below.

At this time, the sweep pulse generating circuit 4 generates one pulse at a time as shown in FIG.
It changes every Hz.

Therefore, stations with frequencies of 50 KHz or even fractions of 10 KHz can be received.

At this time, since the AND gate 9 is closed, the auxiliary counter 8 does not change as described above, but the second and subsequent stages are changed by the carry signal CA from the first stage counter A forming the sweep force counter 5.

That is, until the sweep force counter 5 reaches I1 7 9 3 9 II, the auxiliary counter 8 is I1 7 9 3 0 I+, and when the sweep force counter 5 becomes I+ 7 9 4 0 ++, the auxiliary counter 8 also becomes I1 7 9 3 9 II. ”
7 9 4 0”.

Thus, even during manual sweeping, the auxiliary counter 8 changes by 10.

Next, during manual sweep, the current value of sweep force counter 5 is "7"
Assuming that 90-15MHz is being received at 945”,
The case of switching to automatic sweep will be explained.

When the automatic sweep key 6 is operated in this state where the value of the sweep force counter 5 is I+ 7 9 4 s I+ and the value of the auxiliary counter 8 is "7 9 4 0", the value of the auxiliary counter 8 is first changed by the generation of the preset enable signal PE. I+7
9 4 0 1+ is preset in the sweep force counter 5, and then ten sweep pulses are inputted from the sweep pulse generation circuit 4, so that the sweep force counter 5 immediately changes to I.
f 7 9 5 0 I+.

That is, the state is tuned to 90-2 MHz.

Thereafter, automatic sweeping is performed at 100 KHz intervals as described above.

In this way, even if the sweep force counter 5 is a fractional value during manual sweeping, the auxiliary counter 8 can be changed by operating the automatic sweep key 6.
By presetting the value in the sweep force counter 5, stations with regular frequency allocation can be automatically swept.

Although the above embodiment describes the case of switching from manual sweep to automatic sweep, the case is not limited to this, and when changing from a small tuning step to a large tuning step, for example, when changing from a low speed in manual sweep, This can also be applied when switching from sweep to high-speed sweep.

As described above, the synthesizer receiver of the present invention changes the number of pulses generated from the sweep pulse generation circuit by a sweep operation,
By changing the tuning step, it is possible to receive all stations that deviate from the regular inter-station frequency, and even when receiving stations that deviate from the regular frequency arrangement with a small tuning step using manual sweep. Even when switching to automatic sweep with a large tuning step, stations with regular frequency allocation can be automatically swept by precenting the value of the auxiliary counter to the sweep power counter. It would be useful to apply it to a synthesizer receiver.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a general PLL synthesizer,
FIG. 2 is a diagram showing the configuration of a synthesizer receiver with a changed channel selection step, FIG. 3 is a diagram showing the configuration of the present invention, and FIG.
The figure is a waveform diagram of the main part of Figure 3. 1...Programmable frequency divider, 2...
Voltage controlled oscillator, 3...Reference frequency oscillator, 4
...Sweep pulse generator, 5...Sweep force counter, 6...Auto sweep key, 7...
・Manual sweep key, 8...Auxiliary counter. (4)

Claims (1)

[Claims] 1. The step of configuring the local oscillation circuit with a PLL synthesizer, and selecting a station with a regular inter-office frequency arrangement by changing the frequency division ratio of the programmable frequency dividing means configuring the PLL synthesizer by a sweep operation. In the synthesizer receiver, the synthesizer receiver is provided with a large tuning step changing means for changing the frequency, and a small tuning step changing means for receiving a station having a fraction of the frequency of the regular inter-station frequency allocation. When switching from a sweep of a small tuning step by the small tuning step changing means to a sweep of a large tuning step by the large tuning step changing means, the programmable frequency dividing means constituting the PLL synthesizer is configured to have a regular inter-station frequency allocation. What is claimed is: 1. A synthesizer receiver comprising a setting means for setting a frequency division ratio corresponding to a station at a station, and controlling the sweep operation to be performed in a large tuning step that is a regular inter-office frequency step. 2. The setting means is composed of a sweep counting means for setting the division ratio of the programmable frequency divider constituting the PLL, and an auxiliary counting means that operates in parallel with the counting means, and is configured to vary from a small tuning step to a large tuning step. 2. The synthesizer receiver according to claim 1, wherein the value of the auxiliary counting means is preset to the sweep counting means when switching to the step. 3. The sweep counting means and the auxiliary counting means are simultaneously driven by counting the sweep pulses from the sweep pulse generation circuit during a large tuning step, and the auxiliary counting means is driven by a carry signal from the sweep counting means during a small tuning step. 3. The synthesizer receiver according to claim 2, wherein the synthesizer receiver is driven.