JP2017108452A - High frequency amplifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency amplifier of which the gain adjustment range is wide.SOLUTION: The high frequency amplifier comprises: an input terminal 110 that receives a high frequency signal of an UHF frequency band; an amplification part 140 that amplifies the high frequency signal received by the input terminal; a switch part 130; an adjustment part 150; and an output terminal 170. The amplification part has different three amplification factors, and the three amplification factors can be switched by the switch part. The adjustment part is capable of further finely adjusting the amplification factor of the signal that is amplified by the amplification part. The output terminal outputs the signal that is adjusted by the adjustment part, to external equipment.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a high frequency amplifier for amplifying a high frequency signal.

  There is known a high-frequency amplifier (hereinafter also referred to as “booster”) capable of handling a plurality of input signals having different levels. For example, JP2013-58862A (Patent Document 1) includes an optical operation mode (for example, 70 to 77 MHz), a CATV mode (for example, a downstream signal 70 to 770 MHz, an upstream signal 10 to 60 MHz), and a UHF mode (for example, 470 to 710 MHz or 470 to 770 MHz) has been disclosed.

JP2013-58862A

  In the booster as described above, conventionally, a low gain booster (for example, a gain of 33 dB type) capable of adjusting the gain within a certain gain range according to the input level of the input signal, and higher than the above gain range. A high gain booster (for example, a gain of 43 dB type) capable of adjusting the gain within the gain range was individually lined up.

  In such a case, when a booster is installed, if a sufficient reception level cannot be obtained at the terminal TV terminal even if a low gain booster is used, it must be replaced with a high gain booster. In addition, when a low-gain booster was originally used, the signal attenuation level increased due to a decrease in the level of the input signal or an increase in the number of devices used, resulting in an increase in signal attenuation. When the amplification factor was required, it was necessary to purchase and replace a high gain booster separately. Therefore, the purchase cost of the booster for high gain, and the trouble and cost for replacement were required.

  The present invention has been made to solve such problems, and an object thereof is to provide a high-frequency amplifier having a wide gain adjustment range.

  The high-frequency amplifier according to the present embodiment includes a first input terminal, a first amplifying unit, a first switching unit, a first adjusting unit, and an output terminal. The first input terminal receives a high-frequency signal in the first frequency band. The first amplifying unit has three different amplification factors and amplifies a high-frequency signal in the first frequency band received at the first input terminal. The first switching unit can switch the three amplification factors of the first amplifying unit. The first adjustment unit is configured to be able to continuously adjust the signal amplified by the first amplification unit. The output terminal outputs the signal adjusted by the first adjustment unit.

  Preferably, the first amplifying unit includes first to third attenuators having different attenuation factors and an amplifier that amplifies the signal attenuated by the attenuator.

  Preferably, the high frequency amplifier further includes a second input terminal, a second amplifying unit, a second switching unit, and a second adjusting unit. The second input terminal receives a high-frequency signal in the second frequency band. The second amplifying unit has two different amplification factors and amplifies a high-frequency signal in the second frequency band received at the second input terminal. The second switching unit can switch between the two amplification factors of the second amplification unit. The second adjustment unit adjusts the signal amplified by the second amplification unit, and outputs the adjusted signal via the output terminal.

  Preferably, the first frequency band is a UHF band, and the second frequency band is a satellite broadcast intermediate frequency band.

  According to the present invention, a high-frequency signal (for example, UHF band signal) input to the input terminal can be amplified by switching three different amplification factors, and the gain is further increased by the adjusting unit. A finely adjustable configuration is realized. As a result, a wider gain adjustment range can be realized in the high-frequency amplifier.

It is a functional block diagram which shows the principal part structure of the booster according to Embodiment 1. It is a figure which shows the 1st example of the amplification part of FIG. It is a figure which shows the 2nd example of the amplification part of FIG. It is a functional block diagram which shows the principal part structure of the booster according to Embodiment 2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a functional block diagram showing a main configuration of a high-frequency amplifier (booster) 100 according to the first embodiment of the present invention. The booster 100 shown in FIG. 1 amplifies a high-frequency signal such as a UHF band television signal received by a UHF antenna (not shown) and supplies the amplified signal to a television receiver (not shown). Used to do.

  Referring to FIG. 1, booster 100 includes an input terminal 110, a band pass filter 120, a switching unit 130, an amplification unit 140, an adjustment unit 150, a high pass filter 160, an output terminal 170, and a low pass filter 180. With.

  The input terminal 110 is a terminal for inputting a high frequency signal received by an antenna (not shown).

  The band pass filter 120 is a filter having a pass band corresponding to the high frequency signal supplied to the input terminal 110. When the booster 100 is used for a television signal in the UHF band, the band pass filter 120 has a pass band that can pass a signal in a frequency band of 470 to 710 MHz, for example.

  The amplification unit 140 has three different amplification factors (gains), and is configured such that one of these three amplification factors can be selected by the switching unit 130. The switching unit 130 is, for example, a slide switch, and can be selected by the user from the above three amplification factors by manual operation by the user. Details of the amplification unit 140 will be described later. Although not shown in FIG. 1, for example, a configuration in which the switching unit 130 is automatically switched according to the level of a signal output from the output terminal 170 may be employed.

  The adjustment unit 150 has a function of further finely adjusting the gain of the signal amplified by the amplification unit 140. The adjustment unit 150 is, for example, a rotary variable resistor, and can continuously adjust the signal from the amplification unit 140 in the range of 0 to −10 dB.

  By this amplifying unit 140 and adjusting unit 150, for example, the reception state of radio waves and the level of a received signal attenuated by a cable from an antenna can be adjusted (amplified) to a predetermined range and transmitted to a television receiver.

  The high pass filter 160 has a pass band equal to or higher than the lower limit frequency of the band pass filter 120, and passes only the signal in the pass band among the signals adjusted by the adjustment unit 150 and outputs the signal to the output terminal 170. . The output terminal 170 is connected to an antenna input terminal of a television receiver (not shown) via, for example, a coaxial cable, a duplexer, etc. (none shown), and the amplified UHF television signal is transmitted to the television. Is transmitted to the receiver.

  The low-pass filter 180 has a pass band (for example, 10 MHz or less) through which a low-frequency signal such as a power supply voltage of DC 15 V passes. The low-pass filter 180 is connected to the power supply side terminal of the output terminal 170, and supplies a DC power supply voltage supplied from the outside to the output terminal 170 to the amplification unit 140. The amplifying unit 140 performs an amplifying operation using the power supply voltage supplied from the low pass filter 180. Note that the low-pass filter 180 may be a choke coil.

  Here, in the conventional booster, what can change an amplification factor in two steps was known. In such a booster, there is a limit to the range of the amplification factor that can be used to some extent even by switching between the two amplification factors. For example, a low gain booster that can adjust the gain in the range of 23 to 33 dB, and 31 to 31 High gain boosters capable of adjusting the gain within a range of 41 dB were lined up as individual boosters.

  Then, when a booster capable of adjusting the gain in the range of 23 to 33 dB was used at the beginning, when the number of signal distribution increases or the cable to the booster becomes long and the signal attenuation increases. Further, it is necessary to increase the amplification factor. In this case, since it is necessary to prepare a new booster capable of adjusting the gain in the range of 31 to 41 dB with a higher amplification factor in the conventional case, the purchase cost of the booster and the effort / cost for replacing the booster Is required.

  In the first embodiment as described above, the gain can be switched in three stages by the switching unit 130 of FIG. 1, so that the gain can be adjusted, for example, in a wider gain range of 28 to 43 dB. Is possible. In the first embodiment, the adjustment unit 150 can further adjust the gain in the range of 0 to −10 dB, so that the gain can be substantially adjusted in the range of 18 to 43 dB.

  2 and 3 show a detailed configuration example of the amplifying unit 140 in FIG. Referring to FIG. 2, amplifying unit 140 includes three attenuators 141 to 143 (ATT1 to ATT3) having different attenuation factors and an amplifier 145. The attenuators 141 to 143 are resistors having different values, for example. The attenuator includes the case where the attenuation factor is 0 dB. For example, the attenuation factors of the attenuators 141 to 143 are set to be 0 dB / −10 dB / −15 dB, respectively. One end of each attenuator 141-143 is connected to the input terminal of amplifier 145. The other ends of the attenuators 141 to 143 are connected to switching terminals T1, T2, and T3 of the switching unit 130, respectively.

  The amplifier 145 has a predetermined amplification factor. By combining the attenuators 141 to 143 and the amplifier 145, three different amplification factors can be realized. For example, when the gain of the amplifier 145 is 43 dB, when the attenuator 141 (0 dB) is selected, the total gain of the amplifying unit 140 is 43 dB, and the attenuator 142 (−10 dB) is selected. In this case, the total gain of the amplifying unit 140 is 33 dB, and when the attenuator 143 (−15 dB) is selected, the total gain of the amplifying unit 140 is 28 dB. Further, by adjusting the adjustment unit 150, it is possible to obtain an intermediate gain between them.

  When the input level of the input signal is low, a high amplification factor can be obtained by selecting the attenuator 141 (0 dB), and a desired output level of the output signal can be ensured. As the input level increases, the amplification factor can be reduced by selecting the attenuator 142 (−10 dB) or the attenuator 143 (−15 dB), and the output signal can be adjusted to the desired output level.

  FIG. 3 shows another configuration example of the amplification unit 140 having a different configuration. The amplifier 140A in FIG. 3 includes three amplifiers 146 to 148 (AMP1 to AMP3) having different amplification factors. For example, the amplification factor of the amplifier 146 is 43 dB, the amplification factor of the amplifier 147 is 33 dB, and the amplification factor of the amplifier 148 is 28 dB.

  The input terminals of the amplifiers 146 to 148 are connected to the switching terminals T1, T2, and T3 of the switching unit 130, respectively. Output terminals of the amplifiers 146 to 148 are connected to the adjustment unit 150.

  Also in the configuration of the amplifying unit 140A shown in FIG. 3, the same function as that of the amplifying unit 140 in FIG. 2 can be realized.

  As described above, in a booster for a high-frequency signal such as a UHF band television signal, an amplification unit having three different amplification factors and an adjustment unit capable of continuously adjusting the gain of the signal from the amplification unit are provided. Thus, a wider gain range can be obtained. Therefore, a desired output level can be obtained for a wider input signal level.

  In the above example, the attenuation factor of each attenuator, the amplification factor of each amplifier, and the gain adjustment range in the adjustment unit are examples, and other values may be used. In the above example, the case where the input signal is a high-frequency signal in the UHF band has been described as an example, but may be another frequency band (for example, a VHF band or a satellite broadcast intermediate frequency band).

[Embodiment 2]
In the first embodiment, the case of a booster that amplifies a high-frequency signal in one frequency band has been described. However, the booster according to the present invention amplifies high-frequency signals in different frequency bands and outputs them from a common output terminal. It may be.

  In the second embodiment, in addition to the UHF band signal of the first embodiment, a signal (CS · BS-IF) in a satellite broadcasting intermediate frequency band such as CS (Communication Satellite), BS (Broadcasting Satellite), etc. is amplified. Explain the booster.

  FIG. 4 is a functional block diagram showing a main configuration of booster 200 according to the second embodiment. In FIG. 4, high pass filter 160 in the configuration of booster 100 in the first embodiment is replaced with low pass filter 160 </ b> A, and high pass filter 165, input terminal 210, high pass filters 220 and 260, switching unit 230, and so on. , An amplifying unit 240 and an adjusting unit 250 are provided. In the second embodiment, the description of the elements having the same reference numerals as those of the booster 100 of the first embodiment will not be repeated.

  Referring to FIG. 4, in the booster on the UHF signal side, the signal adjusted by adjustment unit 150 is input to low-pass filter 160A. The low-pass filter 160A has an upper limit frequency of 710 MHz, which is the upper limit frequency of the UHF band, and passes only a signal in the frequency band of 710 MHz or less among the signals from the adjustment unit 150 and outputs the signal to the high pass filter 165.

  The input terminal 210 is a terminal for inputting a high frequency signal in the satellite broadcast intermediate frequency band received by an antenna (not shown) for CS / BS-IF signals.

  The high pass filter 220 is a filter having a pass band corresponding to the high frequency signal received at the input terminal 210. In the second embodiment, since the signal received at input terminal 210 is in the satellite broadcast intermediate frequency band, high-pass filter 220 has a pass band that can pass, for example, a signal in a frequency band of 1032 MHz or higher.

  The amplification unit 240 has two different amplification factors, and is configured so that the switching unit 230 can select one of these two amplification factors. The switching unit 230 is, for example, a slide switch, and one of the switching terminals T4 and T5 is selected by a user's manual operation. Thereby, the amplification factor desired by the user can be selected from the above two amplification factors.

  The details of the amplifying unit 240 may be configured such that there are two attenuators in the amplifying unit 140 and two amplifiers in the amplifying unit 140A. Further, in the amplifying unit 240, similarly to the amplifying unit 140 on the UHF signal side, a configuration in which three different amplification factors can be switched may be employed.

  The adjustment unit 250 has a function of further finely adjusting the gain of the signal amplified by the amplification unit 240. The adjustment unit 250 is a rotary variable resistor similar to the adjustment unit 150, and can continuously adjust the signal from the amplification unit 240 in the range of 0 to -10 dB.

  Similarly to the high-pass filter 220, the high-pass filter 260 has a pass band that allows the CS / BS-IF signal to pass therethrough. Among the signals adjusted by the adjustment unit 250, the high-pass filter 260 passes a signal in the pass band. To the high-pass filter 165.

  The high pass filter 165 receives the UHF signal that has passed through the low pass filter 160 </ b> A and the CS / BS-IF signal that has passed through the high pass filter 260. The high-pass filter 165 is a high-pass filter whose lower limit frequency is 470 MHz, and can pass a signal in which a UHF signal of 470 to 710 MHz and a CS / BS-IF signal of 1032 to 2610 MHz are mixed.

  The signal that has passed through the high-pass filter 165 is output from the output terminal 170 and is output to the television receiver via a coaxial cable (not shown). The mixed signal of the UHF signal and the CS / BS-IF signal is separated into a UHF signal and a CS / BS-IF signal by a branching filter (not shown), and is input to each signal of the television receiver. Is input.

  The low-pass filter 180 supplies the DC power supply voltage supplied from the outside to the output terminal 170 to the amplification units 140 and 240 as in the first embodiment. The amplification units 140 and 240 perform an amplification operation using the power supply voltage supplied from the low pass filter 180. Note that the low-pass filter 180 may be a choke coil.

  As described above, in the second embodiment, it is possible to realize a configuration in which two different high-frequency signals are individually amplified and output from a common output terminal. Then, in one or both of the high-frequency signals, by providing an amplification unit that can be switched to three different amplification factors and an adjustment unit that further adjusts the signal amplified by the amplification unit, a wider gain range than in the past Can be realized.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined not by the above description but by the scope of the utility model registration request, and is intended to include all modifications within the meaning and scope equivalent to the scope of the utility model registration request.

  100, 200 booster, 110, 210 input terminal, 120 band pass filter, 130, 230 switching unit, 140, 140A, 240 amplifying unit, 141, 142, 143 attenuator, 145, 146, 147, 148 amplifier, 150, 250 Adjustment unit, 160 low-pass filter, 160A, 165, 220, 260 high-pass filter, 170 output terminal, T1-T5 switching terminal.

Claims (5)

A first input terminal for receiving a high-frequency signal in a first frequency band;
A first amplifying unit having three different amplification factors and configured to amplify a high-frequency signal in the first frequency band received at the first input terminal;
A first switching unit configured to switch the three amplification factors;
A first adjustment unit configured to continuously adjust the signal amplified by the first amplification unit;
A high frequency amplifier comprising: an output terminal for outputting a signal adjusted by the first adjustment unit. The first amplification unit includes:
First to third attenuators having different attenuation rates;
The high-frequency amplifier according to claim 1, further comprising an amplifier that amplifies the signal attenuated by the attenuator.   The high-frequency amplifier according to claim 1 or 2, wherein the first frequency band is a UHF band. A second input terminal for receiving a high-frequency signal in a second frequency band;
A second amplifying unit having two different amplification factors and configured to amplify a high-frequency signal in the second frequency band received at the second input terminal;
A second switching unit configured to switch between the two amplification factors;
4. The apparatus according to claim 1, further comprising: a second adjustment unit connected to the output terminal and configured to continuously adjust the signal amplified by the second amplification unit. 5. The high frequency amplifier described in 1. The high-frequency amplifier according to claim 4, wherein the second frequency band is a satellite broadcast intermediate frequency band.