JPH07263965A - Microwave frequency converter - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a microwave frequency converter which does not increase frequency conversion loss, is simple in configuration, suitable for miniaturization, and economically advantageous. . A dielectric oscillator 31 having a dielectric resonator 31f coupled to a transmission line 31d having one end connected to a negative resistance element 31a and the other end connected to a terminating resistor 31e, and a negative resistance element 32a at one end. A dielectric oscillator 32 having a dielectric resonator 32f coupled to a transmission line 32d connected to the other end and a terminating resistor 32e.
In the microwave frequency converter that frequency-converts the input signal by mixing the oscillation signal selectively generated from the input signal, the dielectric resonators 31f and 32f are coupled to the same output line 33, The oscillation signals generated by the dielectric oscillators 31 and 32 are derived from the output line 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave frequency converter provided with two local oscillators, and more particularly to an improved extraction of oscillation output from each dielectric oscillator constituting each of the two local oscillators. Regarding

[0002]

2. Description of the Related Art As is well known, recently, television broadcasting systems using geostationary satellites have become widespread.
This type of television broadcasting system can be viewed by subjecting a high-band television broadcasting signal transmitted from a satellite to frequency conversion into a predetermined band by a microwave frequency converter and then performing demodulation processing.

By the way, two kinds of satellites, one for broadcasting and one for communication, are used in such a satellite broadcasting system. For this reason, in order to watch television broadcasts from both satellites, at present, there is a method of providing one microwave frequency converter for each satellite (two in total) and one microwave frequency converter. A method of providing two local oscillators in the container is considered.

Of these, the former method is complicated and large in size and economically disadvantageous. Therefore, the latter method is adopted for practical use. Figure 3
1 shows a conventional microwave frequency converter with two such local oscillators. The microwave frequency converter shown in FIG. 3 frequency-converts both the input horizontal and vertical polarization signals, and uses the configuration shown in Japanese Patent Application Laid-Open No. 60-204104 as two local oscillators. is doing.

Further, this microwave frequency converter takes, for example, an input polarization signal of 11.7 to 12.2 GHz for a communication satellite when a satellite line of the United States is taken as an example.
The frequency is converted to 950 to 1450 MHz by the oscillation signal of 10.75 GHz generated from the local oscillator of the above, and the input polarization signal of 12.2 to 12.7 GHz is generated from the second local oscillator to the broadcasting satellite. 11.2GH
It has a function of frequency conversion to 1000 to 1500 MHz by an oscillation signal of z.

That is, the vertically polarized signal supplied to the input terminal 11 is amplified by the low noise amplifier 12 in the band of 1 GHz of 11.7 to 12.7 GHz, and the band other than the above band by the BPF (band pass filter) 13. After the band component is suppressed, it is supplied to one input terminal of the mixer 14.

First, in the case of frequency-converting the vertically polarized signal from the communication satellite, the negative resistance element 15a and the matching circuit 1 are used.
5b, 15c, a transmission line 15d, a terminating resistor 15e, a dielectric resonator 15f and an output line 15g from a first local oscillator 15 composed of a dielectric oscillator, to apply a bias voltage to the negative resistance element 15a. At 10.75
An oscillation signal of GHz is generated. Then, this oscillation signal is transmitted to the mixer 1 via the BPF 16 for 10.75 GHz.
By being supplied to the other input terminal of 4, the vertically polarized signal is frequency-converted to 950 to 1450 MHz.

At this time, the negative resistance element 17
A second local oscillator 17 including a dielectric oscillator including a, matching circuits 17b and 17c, a transmission line 17d, a terminating resistor 17e, a dielectric resonator 17f, and an output line 17g.
Is controlled so that a bias voltage is not applied to the negative resistance element 17a and an oscillation signal of 11.2 GHz is not generated. Then, 950 output from the mixer 14
Vertically polarized signal frequency-converted to ~ 1450MHz,
After passing through a 2 GHz LPF (low pass filter) 18, it is amplified by an intermediate frequency amplifier 19 and taken out from an output terminal 20.

Further, when frequency-converting a vertically polarized signal from a broadcasting satellite, a bias voltage is applied from the second local oscillator 17 to its negative resistance element 17a.
An oscillation signal of 1.2 GHz is generated. Then, this oscillation signal is supplied to the other input terminal of the mixer 14 via the BPF 21 for 11.2 GHz, whereby the frequency of the vertically polarized signal is converted to 1000 to 1500 MHz.
At this time, the first local oscillator 15 does not apply a bias voltage to the negative resistance element 15a, and the first local oscillator 15 has a voltage of 10.7.
It is controlled so as not to generate an oscillation signal of 5 GHz.

On the other hand, the horizontally polarized signal supplied to the input terminal 22 is amplified by the low noise amplifier 23 in the 1 GHz band of 11.7 to 12.7 GHz, and band components other than the above band are suppressed by the BPF 24. After mixing 25
Is supplied to one of the input terminals. When frequency-converting the horizontally polarized signal from the communication satellite, the first local oscillator 1
The oscillation signal of 5 to 10.75 GHz is generated, and this oscillation signal is supplied to the other input terminal of the mixer 25 via the BPF 26 for 10.75 GHz, so that the horizontal polarization signal has a frequency of 950 to 1450 MHz. To be converted.

At this time, the second local oscillator 1
7 is controlled so as not to generate an oscillating signal, and the horizontal polarization signal frequency-converted to 950 to 1450 MHz output from the mixer 25 is amplified by the intermediate frequency amplifier 28 after passing through the LPF 27 of 2 GHz. Then, it is taken out from the output terminal 29.

When frequency-converting the horizontally polarized signal from the broadcasting satellite, the second local oscillator 17 outputs 11.2 GHz.
z oscillation signal is generated, and this oscillation signal is 11.2 GHz
The horizontally polarized signal is 1000 to 150 by being supplied to the other input terminal of the mixer 25 through the BPF 30 for z.
The frequency is converted to 0 MHz. At this time, the first local oscillator 15 is controlled so as not to generate an oscillation signal.

FIG. 4 shows another example of a conventional microwave frequency converter having two local oscillators. The microwave frequency converter shown in FIG. 4 shows a circuit configuration in the case of frequency-converting either a vertical or horizontal polarization signal (11.7 to 12.7 GHz). That is,
In FIG. 4, when the frequency of the vertically polarized signal is converted, the input terminal 11, the low noise amplifier 12, the BPF 13, the mixer 14, the BPF 16, the LPF 18, the intermediate frequency amplifier 1
It can be considered that 9, the output terminal 20 and the BPF 21 are used.

Further, in the case where the frequency of the horizontally polarized signal is converted, as shown in parentheses in FIG.
Low noise amplifier 23, BPF 24, mixer 25, BPF2
6, the LPF 27, the intermediate frequency amplifier 28, the output terminal 29 and the BPF 30 may be considered to be used. In addition,
The first and second local oscillators 15 and 17 are commonly used for frequency conversion of both vertical and horizontal polarized signals, and one ends of their output lines 15g and 17g are terminated by termination resistors 15h and 17h, respectively. Has been done.

By the way, in the conventional microwave frequency converter configured as described above, the first local oscillator 1
The oscillation signal output from the second local oscillator 17 and the oscillation signal output from the second local oscillator 17
BPF1 in order to be efficiently supplied to
6 and 26, the oscillation signal output from the first local oscillator 15 is passed, but the oscillation signal output from the second local oscillator 17 is sufficiently suppressed, and as the BPFs 21 and 30, , The second local oscillator 1
The oscillation signal output from the first local oscillator 15 is allowed to pass, but the oscillation signal output from the first local oscillator 15 needs to be sufficiently suppressed.

For example, the BPFs 16 and 26 allow the oscillation signal of 10.75 GHz output from the first local oscillator 15 to pass, while the input polarized signal of 11.7 to 12.7 GHz and the second local oscillator. Output from 17.
It has a characteristic of suppressing an oscillation signal of 2 GHz, and BPF2
1 and 30 are output from the second local oscillator 15 as 1
While passing a 1.2 GHz oscillation signal, 11.7-
Input polarization signal of 12.7 GHz and first local oscillator 1
It is necessary to have a characteristic of suppressing an oscillation signal of 10.75 GHz output from the signal No. 5.

However, in the BPFs 21, 30 and 16, 26 which are generally used in the microwave band and which are formed by forming a microstrip line on a dielectric substrate, the first and second local oscillators 15 are used. , 1
It is technically difficult to set the frequency band to be passed to a narrow band in order to mutually suppress the oscillating signals output from No. 7, and if the design is made narrow band, the pass loss increases and the mixers 14, 25 Since the injection level of the oscillating signal is reduced, the frequency conversion loss increases. Further, since the conventional microwave frequency converter requires four BPFs 16, 26, 21, and 30, they occupy a large area on the dielectric substrate,
It is also a factor that causes an increase in size and economic disadvantage.

[0018]

As described above, in the conventional microwave frequency converter having the two local oscillators, the BPF is used to isolate the two local oscillators from each other. However, there is a problem that the injection level of the locally oscillated signal to the mixer is lowered and the frequency conversion loss is increased. In addition, there is a disadvantage that the BPFs are large in size and economically disadvantageous because they are constructed.

Therefore, the present invention has been made in consideration of the above circumstances, and is an extremely good microwave frequency converter which is economically advantageous, suitable for miniaturization without increasing frequency conversion loss, and has a simple structure. The purpose is to provide a container.

[0020]

A microwave frequency converter according to the present invention has a first transmission line having a first negative resistance element connected to one end and a first terminating resistor connected to the other end. A first dielectric oscillator to which the first dielectric resonator is coupled, and a second transmission line having a second negative resistance element connected to one end and a second terminating resistor connected to the other end. A second dielectric oscillator to which two dielectric resonators are coupled, and an input signal is generated by mixing an oscillation signal selectively generated from the first and second dielectric oscillators with the input signal. It is intended for frequency conversion. Then, the first and second dielectric resonators are coupled to the same output line, and an oscillation signal generated by the first and second dielectric oscillators is derived from the output line. .

[0021]

According to the above-mentioned structure, the first and second dielectric resonators are coupled to the same output line, and the oscillation signals generated by the first and second dielectric oscillators from this output line. Therefore, the isolation between the first and second dielectric oscillators is formed by forming a microstrip line on a dielectric substrate as in the conventional case.
It becomes dependent on the first and second dielectric resonators instead of the PF. Therefore, since the BPF for guiding the oscillation signals output from the first and second dielectric oscillators to the mixer can use a wide band, the injection level of the local oscillation signal to the mixer is lowered. This can be prevented, and the frequency conversion loss can be prevented from increasing. Further, since the number of BPFs is small, the configuration is simple, suitable for downsizing, and economically advantageous.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1, the same parts as those in FIG. 3 are designated by the same reference numerals. That is, reference numeral 31 in FIG.
Is a first local oscillator, which includes a negative resistance element 31a, matching circuits 31b and 31c, a transmission line 31d, a terminating resistor 31e, and a dielectric resonator 31f, and oscillates at an oscillation frequency of 10.75 GHz. Is. Further, reference numeral 32 in FIG. 1 denotes a second local oscillator, which is a negative resistance element 32.
a, matching circuits 32b and 32c, a transmission line 32d, a terminating resistor 32e, and a dielectric resonator 32f, and 11.2GH
It is a dielectric oscillator that oscillates at an oscillation frequency of z. The dielectric resonators 31f and 32f of the first and second local oscillators 31 and 32 are coupled to the common output line 33.

First, when the polarization signal from the communication satellite is frequency-converted, a bias voltage is applied to the negative resistance element 31a of the first local oscillator 31, and the negative resistance element 32a of the second local oscillator 32 is applied. Do not apply a bias voltage to. Then, the first local oscillator 31 starts the oscillating operation at the oscillation frequency of 10.75 GHz determined by the dielectric resonator 31f. Then, the 10.75 GHz oscillation signal generated by the first local oscillator 31 is output by the output line 3
3 connected to both ends of the output line 33 and having the same load impedance as each other,
35 are evenly distributed and supplied to the mixers 14, 25.

At this time, the dielectric resonator 32f of the second local oscillator 32 is also coupled to the output line 33. This coupling causes the oscillation frequency of the second local oscillator 32 (11.2).
It is a very narrow band coupling only near (GHz). For this reason, the first local oscillator 3 previously derived to the output line 33 is
The 10.75 GHz oscillation signal from 1 is not affected by the dielectric resonator 32f of the second local oscillator 32.

Similarly, in the case of frequency-converting the polarization signal from the broadcasting satellite, a bias voltage is applied to the negative resistance element 32a of the second local oscillator 32, and the first local oscillator 31 is supplied.
No bias voltage is applied to the negative resistance element 31a. Then, the second local oscillator 32 starts the oscillating operation at the oscillation frequency of 11.2 GHz determined by the dielectric resonator 32f. The 11.2 GHz oscillation signal generated by the second local oscillator 32 is derived from the output line 33 without being affected by the dielectric resonator 31f of the first local oscillator 31, and then the BPF 34, 3 is generated.
5 are evenly distributed and supplied to the mixers 14 and 25.

Therefore, according to the configuration of the above embodiment, the dielectric resonators 31f and 32f forming the first and second local oscillators 31 and 32 are coupled to the same output line 33, and the output Since the oscillation signals generated by the first and second local oscillators 31 and 32 are derived from the line 33, the isolation between the first and second local oscillators 31 and 32 is the same as in the conventional case. It becomes dependent on the dielectric resonators 31f and 32f instead of the BPF formed by forming the microstrip line on the dielectric substrate.

Therefore, the first and second local oscillators 3 are
The BPFs 34 and 35 for guiding the oscillation signals output from the mixers 1 and 32 to the mixers 14 and 25 are 10.75 GH.
Since it may have a pass characteristic for an oscillating signal of z and an oscillating signal of 11.2 GHz, and have a characteristic of suppressing an input polarization signal of 11.7 to 12.7 GHz, it has a wider band than the conventional one. Since it is possible to use the above-mentioned one, the passage loss is small, it is possible to prevent the injection level of the oscillation signal into the mixers 14 and 25 from being lowered, and it is possible to prevent the frequency conversion loss from increasing. Also, BPF 34,3
Since the number of 5 is smaller than the conventional one, the structure is simple, suitable for downsizing, and economically advantageous.

Next, FIG. 2 shows a modification of the above embodiment. That is, the output line 36 for guiding the oscillation signals output from the first and second local oscillators 31, 32 to the mixer 14, and the output line 36 for the mixer 25 output from the first and second local oscillators 31, 32. An output line 37 for guiding an oscillating signal is provided separately, and the output lines 36 and 37 are both provided with the dielectric resonator 31 of the first and second local oscillators 31 and 32.
The terminal resistors 36a and 37a are connected to the ends of the output lines 36 and 37 on the side not connected to the BPFs 34 and 35, respectively.

With this structure, the same effects as those of the above-described embodiment can be obtained, and the mixers 14 and 25 can output the output lines 36 and 37 and the dielectric resonators 31f and 32f.
Since they are indirectly coupled via the mixers 14, 2
The isolation between the five can also be improved. The present invention is not limited to the above embodiment,
In addition, various modifications can be made without departing from the scope of the invention.

[0030]

As described above in detail, according to the present invention,
It is possible to provide an extremely good microwave frequency converter which is suitable for downsizing without increasing the frequency conversion loss, has a simple structure, and is economically advantageous.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a microwave frequency converter according to the present invention.

FIG. 2 is a block diagram showing a modification of the embodiment.

FIG. 3 is a block configuration diagram showing a conventional microwave frequency converter.

FIG. 4 is a block diagram showing another conventional microwave frequency converter.

[Explanation of symbols]

11 ... Input terminal, 12 ... Low noise amplifier, 13 ... BPF,
14 ... Mixer, 15 ... 1st local oscillator, 16 ... BP
F, 17 ... Second local oscillator, 18 ... LPF, 19 ... Intermediate frequency amplifier, 20 ... Output terminal, 21 ... BPF, 22 ...
Input terminal, 23 ... Low noise amplifier, 24 ... BPF, 25 ...
Mixer, 26 ... BPF, 27 ... LPF, 28 ... Intermediate frequency amplifier, 29 ... Output terminal, 30 ... BPF, 31 ... First local oscillator, 32 ... Second local oscillator, 33 ... Output line, 34, 35 ... BPF, 36, 37 ... Output line.

Claims (1)

[Claims] 1. A first transmission line having a first negative resistance element connected to one end and a first terminating resistor connected to the other end.
A first dielectric oscillator coupled to the second dielectric resonator and a second transmission line having a second negative resistance element connected to one end and a second terminating resistor connected to the other end. A second dielectric oscillator to which a dielectric resonator is coupled, and mixing the oscillation signal selectively generated from the first and second dielectric oscillators with the input signal to generate the input signal In a microwave frequency converter for frequency conversion, the first and second dielectric resonators are coupled to the same output line, and an oscillation signal generated by the first and second dielectric oscillators from the output line. A microwave frequency converter characterized in that it is configured so as to derive.