JP2003069428A - Multi-band pll circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized multi-band PLL circuit for a 7 GHz band and a 10 GHz band that eliminates the need for individual provision of the configuration for the 7 GHz band and the 10 GHz band. SOLUTION: A PLL control section 8 is used in common for the 7 GHz band and the 10 GHz band and provided with changeover devices 7, 11 that select the input and a loop filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-band PLL circuit that switches between a 7 GHz band frequency signal and a 10 GHz band frequency signal to generate an oscillation signal having a stable frequency.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional 7 GHz band oscillator and 10
Multi-band P that generates by switching the GHz band oscillator
It is a block diagram which shows the structural example of a LL circuit. As shown in FIG. 2, the 7 GHz band frequency PLL circuit and the 10 GHz band frequency PLL circuit are individually provided. Each P
The LL circuit individually has a VCO, a PLL control unit, a loop filter, a frequency divider, a power amplification unit, a distribution unit, and a reference signal oscillator.

Each of the PLL circuits divides the VCO output into two by a divider, outputs one to the power amplifier and one to the frequency divider, and the frequency divider fixedly divides the input signal and PLL. Output to the control unit. In addition, the PLL control unit dynamically changes the frequency division ratio by channel control to divide the frequency of the input signal, and then detects the phase difference from the reference signal with the phase comparator,
Output to loop filter. Further, the phase difference detection signal is smoothed by the loop filter, and then the VCO
A feedback loop is built in so that the VCO output frequency is stabilized by inputting to the frequency control terminal.

In each of the PLL circuits, the frequency-stabilized 7 GHz band frequency signal and 10 GHz band frequency signal are power-amplified to a specified value in each power amplification section, and then band-limited by the BPF duplexer and output. To be done.
Here, the 7 GHz band frequency signal and the 10 GHz band frequency signal are switched by the ON / OFF control of each power amplification unit.

[0005]

[Problems to be Solved by the Invention] Conventional multi-band P
The LL circuit has a drawback that the circuit scale becomes large because the PLL control section is separately provided for the 7 GHz band and the 10 GHz band. An object of the present invention is to eliminate this drawback and to provide a multi-band PLL circuit having a compact structure.

[0006]

In order to achieve the above-mentioned object, the present invention uses a common PLL control unit in the 7 GHz band and the 10 GHz band.

[0007]

DETAILED DESCRIPTION OF THE INVENTION A multi-band PLL according to the present invention.
One embodiment of the circuit will be described with reference to FIG. Figure 1
FIG. 1 is a diagram showing an embodiment of the present invention, in which a 7 GHz band and 1
Multi-band P sharing the PLL control unit in the 0 GHz band
It is a block diagram which shows the structural example of a LL circuit.

In the figure, 1 is a 7 GHz VCO for transmitting a 7 GHz band signal, and 2 is a 10 GHz for transmitting a 10 GHz band signal.
GVCO, 3 is a 7G divider that divides a 7GHz band signal into two, 4 is a 10G divider that divides a 10GHz band signal into two, and 5 is a 7G divider that fixedly divides a 7GHz band signal, 6 Is a 10 G frequency divider for fixedly dividing a 10 GHz band signal, and 7 is an R for switching an input signal to the PLL control unit.
F switching device, 8 is a PLL control unit having a function of dynamically changing the frequency division ratio according to channel switching and a phase comparison function of detecting a phase difference between the reference signal source, and 9 is a 7 GHz band signal. Sometimes a 7G loop filter that smoothes the phase difference detection output, 10 is a 10G loop filter that smoothes the phase difference detection output when a signal in the 10 GHz band, 11 is a loop filter switch that switches between a 7G loop filter and a 10G loop filter, 12 is a 7G power amplifier that amplifies a 7 GHz band signal to a specified value, 13 is a 10 G power amplifier that amplifies a 10 GHz band signal to a specified value, and 14 is
A BPF duplexer for band limiting the 7 GHz band signal and the 10 GHz band signal power-amplified to a specified value, 15 is channel switching data that dynamically gives a frequency division ratio to the PLL control unit at the time of channel switching, and 16 is 7 GHz / 10 GHz The reference numeral 17 designates a reference signal source for outputting a sufficiently stable reference signal.

Next, the operation of this embodiment will be described. Figure 1
As shown in, the output signal of the 7GVCO 1 is divided into two by the 7G distribution unit 3, one is power-amplified to a specified value by the 7G power amplification unit 12, and one is fixedly frequency-divided by the 7G frequency divider 5 to be RF-divided. It is input to the switch 7. Further, the output signal of the 10 GVCO 2 is also distributed and fixedly frequency-divided and input to the RF switch 7 as in the 7 GHz band.

The RF switching unit 7 switches between a 7 GHz band signal and a 10 GHz band signal according to a local switching signal and outputs the P signal.
Output to the LL control unit 8.

The PLL controller 8 divides the signal input from the RF switch 7 by the frequency division ratio indicated by the channel switch signal 15, and compares the phase with a sufficiently stable reference signal by the phase comparator. Then, the phase difference signal is output.

The loop filter switching unit selects the 7G loop filter 9 or the 10G loop filter 10 according to the local switching signal, and the selected loop filter smooths the phase difference signal output from the PLL control unit 8, Output to the frequency control terminals of 7GVCO1 and 10GVCO2. Also, the local switching signal is 7 GHz
The output of the 10G power amplifier and the 10GVCO is cut off in the band, and the 7G power amplifier and the 7GVCO are cut in the band of 10GHz.
Controls to turn off the output of.

[0013]

According to the present invention, a 7 GHz band PLL and 1
It is possible to provide a small-sized multi-band PLL circuit by sharing the PLL control unit in the 0 GHz band PLL and controlling the outputs of the VCO and the power amplification unit so that the signals do not collide with each other.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a multiband PLL circuit according to the present invention.

FIG. 2 is a block diagram showing a configuration example of a multiband PLL circuit according to a conventional technique.

[Explanation of symbols]

1: 7 GVCO, 2:10 GVCO, 3: 7 GVCO,
4: 10G distribution unit, 5: 7G frequency divider, 6: 10G frequency divider, 7: RF switching unit, 8: PLL control unit, 9: 7G loop filter, 10: 10G loop filter, 11: loop filter switching unit , 12: 7G power amplifier, 13:10
G power amplifier, 14: BPF duplexer, 15: channel switching data, 16: local switching signal, 17: reference signal source.

Claims (3)

[Claims] 1. A multi-mode multi-function device, wherein a PLL control unit for a 7 GHz band frequency signal and a PLL control unit for a 10 GHz band frequency signal are commonly used to generate either one of the frequency band signals. Band PLL circuit. 2. The multi-band PLL circuit according to claim 1, wherein the 7-GHz band frequency signal and the 10-GHz band frequency signal are switched and input to the PLL control unit. 3. The multiband PLL circuit according to claim 1, wherein when selecting a frequency band signal to be generated, a different loop filter is selectively selected. .