GB2235340A - Signal receiver for satellite broadcast - Google Patents
Signal receiver for satellite broadcast Download PDFInfo
- Publication number
- GB2235340A GB2235340A GB9008743A GB9008743A GB2235340A GB 2235340 A GB2235340 A GB 2235340A GB 9008743 A GB9008743 A GB 9008743A GB 9008743 A GB9008743 A GB 9008743A GB 2235340 A GB2235340 A GB 2235340A
- Authority
- GB
- United Kingdom
- Prior art keywords
- amplifier
- polarized waves
- receiving
- waveguide
- transistor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000523 sample Substances 0.000 claims abstract description 14
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 claims abstract description 8
- 230000005669 field effect Effects 0.000 claims abstract description 6
- 230000010287 polarization Effects 0.000 abstract description 5
- 230000004048 modification Effects 0.000 abstract description 2
- 238000012986 modification Methods 0.000 abstract description 2
- 238000002955 isolation Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 235000006693 Cassia laevigata Nutrition 0.000 description 1
- 241000522641 Senna Species 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/10—Auxiliary devices for switching or interrupting
- H01P1/15—Auxiliary devices for switching or interrupting by semiconductor devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/16—Auxiliary devices for mode selection, e.g. mode suppression or mode promotion; for mode conversion
- H01P1/161—Auxiliary devices for mode selection, e.g. mode suppression or mode promotion; for mode conversion sustaining two independent orthogonal modes, e.g. orthomode transducer
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/189—High-frequency amplifiers, e.g. radio frequency amplifiers
- H03F3/19—High-frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only
- H03F3/193—High-frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only with field-effect devices
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/294—Indexing scheme relating to amplifiers the amplifier being a low noise amplifier [LNA]
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/372—Noise reduction and elimination in amplifier
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Abstract
A signal receiver has probe antennas 2a, 2b provided in a waveguide 1 for receiving differently polarized waves eg both vertical and horizontal polarized waves. The probe antennas 2a, 2b are arranged in relation to intersect at right angles respectively in the waveguide 1, wherein each antenna 2a, 2b is connected to input terminals 10, 20 of an amplifier respectively. According to the structure, it is possible to receive both vertical and horizontal polarized waves simultaneously without using a rotational probe antenna. In a modification clockwise and anti-clockwise circular polarization waves can be received. The amplifiers may each include a gallium arsenic field effect transistor (4, 5 Fig 4) selectively switched on to receive the required vertical or horizontal polarized waves. <IMAGE>
Description
SATELLITE BROADCAST SIGNAL RECEIVER
The present invention relates to a converter for satellite broadcast signal receiving systems in which both horizontally and vertically polarised signals can be received using a single waveguide and amplifier.
In broadcasting via satellite, different kinds of polarized waves, such as vertically and horizontally polarized waves, are sent mixed together in some regions. In regions like this, a plurality of signals with differing polarization should be received at the same time, and the receiver should select the signals of the desired polarization.
As shown in Fig. 6 a waveguide 1 is attached to a converter which is provided on an antenna for receiving signals from a satellite, and a probe antenna 2 for guiding the signal into coaxial cables is provided in the waveguide 1. Conventionally, a single probe antenna 2 is provided in parallel with the electric field vector of the waves to be received.
As shown in Fig. 7(a) & (b), a low noise amplifier (hereinafter referred to as LNA) in a low noise blockdown converter (hereinafter referred to as LNB) for receiving satellite broadcasting signals consists of two or three stages, with a single input terminal. The LNA includes amplifying elements having low noise characteristics, such as a gallium arsenic field effect transistor (GaAs.FET) or a high electronic mobility transistor (HEMT).
In conventional structure, when both vertical and horizontal polarized waves exist together in the receiving channel, it is necessary to rotate the probe antenna by an angle of 90 degrees using a motor or the like, which results ,in a complicated structure and high cost.
Further, it is desirable to improve isolation when receiving both vertically and horizontally polarized waves.
An aim of the present invention is to provide a converter which is capable of receiving both vertically and horizontally polarized waves simultaneously by arranging antennae for receiving both vertically and horizontally polarized waves which intersect at right angles, and the cost of which can be reduced with a simplified structure, and in which the isolation of the input wave can be improved.
According to the present invention, there is provided an apparatus for receiving a satellite broadcasting signal comprising:
a waveguide for guiding polarized waves,
probe antennae for receiving vertical and horizontal polarized waves arranged perpendicular to one another in the waveguide, and
an amplifier for amplifying the received signal having input terminals each of which is connected to a different one of the antennae.
The invention also provides an amplifier for receiving a satellite broadcasting signal comprising:
an amplifier for amplifying both vertically and horizontally polarized waves comprising a plurality of amplifier stages each having a high electronic mobility transistor or a gallium arsenic field effect transistor, wherein a first stage amplifier is provided for each input terminal for vertically or horizontally polarized signals, wherein in use the power source for the transistor of the first stage amplifier for receiving which ever one of the vertically or horizontally polarized waves is not desired can be switched OFF.
The above aspects can, of course, be employed in combination.
Further, a gate and a drain in the transistor for receiving either of vertical or horizontal polarized wave which is not to be desired to receive are applied reverse bias voltage.
With the present invention, both vertical and horizontal polarized waves can be received simultaneously without rotating the probe antenna.
Further, both vertical and horizontal polarized waves can be received simultaneously and easily while keeping the input terminals appropriately isolated.
Further, isolation between input terminals is ensured effectively.
The present invention will be further explained hereinafter with reference to the following description of an exemplary embodiment, and the accompanying drawings, in which:
Fig. 1 is a side view of a waveguide used for a converter receiving satellite broadcasting signal of an embodiment of the present invention;
Fig. 2 is a cross sectional view of line II to II in Fig. 1;
Fig. 3 is a block diagram of the converter in the embodiment of the present invention;
Fig. 4 is a circuit diagram showing structure of the converter;
Fig. 5 is a characteristic diagram showing isolation effect b applying reverse bias voltage;
Fig. 6 is a lateral view of a waveguide used in a conventional converter; anc
Fig. 7 (a) (b) are block diagrams of amplifiers used ir. the conventional converters.
An embodiment of the present invention will now be described with reference to Figs. 1 to 5.
Figs. 1 and 2 show a side and a sectional view of a waveguide. Probe antennas 2a and 2b for receiving vertically and horizontally polarized waves are arranged perpendicular to one another in a circular waveguide 1.
According to the above structure, it is not necessary tc rotate the probe antenna for an angle of 90 degrees corresponding to a receiving channel, then the construction can be simplified,
Fig. 3 shows a block structure of the low noise block down converter (LNB). The low noise amplifier (LNA) has input terminals 10,20 to which probe antennas 2a, 2b is connected and includes a first stage amplifier designed for each input terminals 10,20 thereto. An output signal from each amplifier and an output from a local oscillator (leo) (for example, oscillation output of 10.678GHz) are mixed in a mixer (MIX), and an output from the mixer (MIX) is amplified by an intermediate frequency amplifier (IF), then applied to a receiver 3.
With the parallel arrangement of input section as mentioned above, it is easier to receive also a reverse polarized wave signal so that it is possible to reduce the cost of the antenna system.
Fig. 4 shows a structure of abovementioned LNA. The probe antennas 2a, 2b are connected to the input terminals 10,20 respectively. Eac amplifler includes amplifier transistr. 4,5, and 6 having characteristic of low noise, such as a high electr--i mobility transistor (HEMT) or a field effect transistor (GaAs Foe). Control circuits for driving each of the first stage transistors 4 and 5 are connected to power sources
A,B and C,D respectively.
When the input terminal 10 is used, the power sources C and
D for the transistor 5 of the first stage amplifier correspondlng to the input terminal 20 are made OFF state, so that zero bia voltage (0 volt) between a gate and a drain is applied, the lation between the input terminals 10 and 20 can be made large. As a result, only the signal of the input terminal 10 is transmitted to the latter stage amplifier. Then, it is possible to shut off either of the vertical or horizontal polarized wave signal in a satellite broadcasting signal of which a receiver does not intend to receive, and to select the wave to be received. In the case of using the input terminal 20, similar operation can be achieved by setting the state to the contrary to the above.
In order to make the isolation of the input terminals 10 and 20 more effectively, reverse bias voltage is applied on the transistors 4 or 5 which is in the operating side. To apply reverse bias voltage, drain voltage is made fix and gate voltage is made pinch off voltage or lower voltage than it. For example, when the input terminal 20 is adapted, the voltage for the power source A of the transistor 4 in the input terminal IC is -i .
and the voltage for the power source B is 2V, and the voltage for the power source C of the transistor 5 in the input terminal 20 which is in operating side is -0.5V, and the power source D is 2V.
Fig. 5 shows the improvement of the isolation between the input terminals 10 and 20 caused by applying reverse bias voltage on the side of no-operating. As it will be appreciated from the drawing, the isolation is improved for 5 to 10 db.
According to the present invention, as abovementioned, since sennas for receiving both vertical and horizontal polarized waves are arranged in relation to intersect at right angles respectively in the waveguide of the low noise blockdown converter (LNB), reverse polarized waves are received simultaneou-sly so that it is needless to rotate a probe antenna for an angle of 90 degrees when a receiving channel is changed.
Accordingly, the structure of the antenna for rotation is not required so that the structure can be simplified and the cost can be reduced.
Further, the amplifier includes the high electronic mobility transistor or the gallium arsenic field effect transistor (GaAs
FET), while the first stage amplifier is provided corresponding to each input terminal of vertical or horizontal polarized wave respectively, and either cf the power source for the transistor in the first stage amplifier of which receiver does not intend to receive is switched OFF, se that the system is simplified and the polarized wave of a channel of which receiving is to be desired can be easily received selectively.
Further, reverse bias voltage is applied on the transistor in the first stage amplifier of which the receiver does not intend to receive so that the effect of the isolation between the input terminals are insured.
It will be appreciated that modification may be made in the present invention. For example, the present invention can be applied to broadcasting signals of clockwise and anti-clockwise circular polarization, instead of vertical and horizontal polarization as previously described.
Claims (5)
1. An apparatus for receiving a satellite broadcasting signal comprising:
a waveguide for guiding polarized waves,
probe antennae for receiving vertical and horizontal polarized waves arranged perpendicular to one another in the waveguide, and
an amplifier for amplifying the received signal having input terminals each of which is connected to a different one of the antennae.
2. An amplifier for receiving a satellite broadcasting signal comprising:
an amplifier for amplifying both vertically and horizontally polarized waves comprising a plurality of amplifier stages each having a high electronic mobility transistor or a gallium arsenic field effect transistor, wherein a first stage amplifier is provided for each input terminal for vertically or horizontally polarized signals, wherein in use the power source for the transistor of the first stage amplifier for receiving which ever one of the vertically or horizontally polarized waves is not desired can be switched OFF.
3. An amplifier according to claim 2, wherein a reverse biased voltage is applied to the transistor which receives whichever one of the vertically or horizontally polarized waves is not desired.
4. An apparatus according to claim 1, wherein said amplifier comprises an amplifier according to claim 2 or 3.
5. An apparatus for receiving a satellite broadcasting signal constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 5 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9831289U JPH0336243U (en) | 1989-08-22 | 1989-08-22 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9008743D0 GB9008743D0 (en) | 1990-06-13 |
| GB2235340A true GB2235340A (en) | 1991-02-27 |
| GB2235340B GB2235340B (en) | 1994-05-11 |
Family
ID=14216408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9008743A Expired - Lifetime GB2235340B (en) | 1989-08-22 | 1990-04-18 | Satellite broadcast signal receiver |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH0336243U (en) |
| GB (1) | GB2235340B (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992022937A1 (en) * | 1991-06-14 | 1992-12-23 | Cambridge Computer Limited | High isolation switch |
| ES2036940A2 (en) * | 1991-11-05 | 1993-06-01 | Cesel S A Ceselsa | Probe antenna |
| GB2289810A (en) * | 1994-05-20 | 1995-11-29 | Microelectronics Tech Inc | An r.f. switch using transistors as switch and gain elements |
| EP0735603A1 (en) * | 1995-03-25 | 1996-10-02 | Philips Patentverwaltung GmbH | Circuit for processing a first or a second high frequency signal |
| EP0757400A1 (en) * | 1995-08-03 | 1997-02-05 | THOMSON multimedia S.A. | Microwave polariser |
| US5760659A (en) * | 1995-08-03 | 1998-06-02 | Thomson Multimedia S.A. | Microwave polariser |
| EP1251582A1 (en) * | 2001-04-17 | 2002-10-23 | Abb Research Ltd. | Data transmission system |
| RU2450393C1 (en) * | 2010-10-21 | 2012-05-10 | Федеральное государственное унитарное предприятие "Научно-производственное предприятие "Исток" (ФГУП НПП "Исток") | Shf switch |
| US8494476B2 (en) | 2005-11-01 | 2013-07-23 | Diodes Incorporated | Monolithic LNA support IC |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4657486B2 (en) * | 2001-03-09 | 2011-03-23 | 十四男 市川 | Continuous crystallization method for crystalline resin pellet molding |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1189463A (en) * | 1966-07-08 | 1970-04-29 | Hughes Aircraft Co | Improvements in and relating to antenna system |
| GB2037111A (en) * | 1978-11-15 | 1980-07-02 | Pioneer Electronic Corp | Signal change-over amplifier |
| EP0126354A2 (en) * | 1983-05-19 | 1984-11-28 | Deutsche Thomson-Brandt GmbH | Input circuit arrangement for a television receiver |
| EP0228947A1 (en) * | 1985-12-10 | 1987-07-15 | Société S E R E L | Superheterodyne receiver for two microwave signals with two opposite circular polarizations |
| EP0235846A2 (en) * | 1986-03-03 | 1987-09-09 | Siemens Telecomunicazioni S.P.A. | Dual polarization microwave receiver for direct reception from a broadcasting satellite |
| GB2188493A (en) * | 1986-03-27 | 1987-09-30 | Era Patents Ltd | Orthogonal mode transducer |
| EP0275587A1 (en) * | 1986-12-19 | 1988-07-27 | Philips Electronique Grand Public | Very high frequency electronic switch |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5443659A (en) * | 1977-09-13 | 1979-04-06 | Tech Res & Dev Inst Of Japan Def Agency | Antenna unit |
-
1989
- 1989-08-22 JP JP9831289U patent/JPH0336243U/ja active Pending
-
1990
- 1990-04-18 GB GB9008743A patent/GB2235340B/en not_active Expired - Lifetime
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1189463A (en) * | 1966-07-08 | 1970-04-29 | Hughes Aircraft Co | Improvements in and relating to antenna system |
| GB2037111A (en) * | 1978-11-15 | 1980-07-02 | Pioneer Electronic Corp | Signal change-over amplifier |
| EP0126354A2 (en) * | 1983-05-19 | 1984-11-28 | Deutsche Thomson-Brandt GmbH | Input circuit arrangement for a television receiver |
| US4596045A (en) * | 1983-05-19 | 1986-06-17 | Deutsche Thomson-Brandt Gmbh | Input circuit for television receiver |
| EP0228947A1 (en) * | 1985-12-10 | 1987-07-15 | Société S E R E L | Superheterodyne receiver for two microwave signals with two opposite circular polarizations |
| EP0235846A2 (en) * | 1986-03-03 | 1987-09-09 | Siemens Telecomunicazioni S.P.A. | Dual polarization microwave receiver for direct reception from a broadcasting satellite |
| GB2188493A (en) * | 1986-03-27 | 1987-09-30 | Era Patents Ltd | Orthogonal mode transducer |
| EP0275587A1 (en) * | 1986-12-19 | 1988-07-27 | Philips Electronique Grand Public | Very high frequency electronic switch |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992022937A1 (en) * | 1991-06-14 | 1992-12-23 | Cambridge Computer Limited | High isolation switch |
| ES2036940A2 (en) * | 1991-11-05 | 1993-06-01 | Cesel S A Ceselsa | Probe antenna |
| GB2289810A (en) * | 1994-05-20 | 1995-11-29 | Microelectronics Tech Inc | An r.f. switch using transistors as switch and gain elements |
| EP0735603A1 (en) * | 1995-03-25 | 1996-10-02 | Philips Patentverwaltung GmbH | Circuit for processing a first or a second high frequency signal |
| US5774093A (en) * | 1995-03-25 | 1998-06-30 | U.S. Philips Corporation | Circuit arrangement for processing a first or a second high-frequency signal |
| EP0757400A1 (en) * | 1995-08-03 | 1997-02-05 | THOMSON multimedia S.A. | Microwave polariser |
| US5760659A (en) * | 1995-08-03 | 1998-06-02 | Thomson Multimedia S.A. | Microwave polariser |
| EP1251582A1 (en) * | 2001-04-17 | 2002-10-23 | Abb Research Ltd. | Data transmission system |
| US8494476B2 (en) | 2005-11-01 | 2013-07-23 | Diodes Incorporated | Monolithic LNA support IC |
| RU2450393C1 (en) * | 2010-10-21 | 2012-05-10 | Федеральное государственное унитарное предприятие "Научно-производственное предприятие "Исток" (ФГУП НПП "Исток") | Shf switch |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2235340B (en) | 1994-05-11 |
| GB9008743D0 (en) | 1990-06-13 |
| JPH0336243U (en) | 1991-04-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Expiry date: 20100417 |