WO2002091574A1

WO2002091574A1 - Switching electronic relay

Info

Publication number: WO2002091574A1
Application number: PCT/CZ2002/000026
Authority: WO
Inventors: Marian VÁNA
Original assignee: Vana Marian
Priority date: 2001-05-04
Filing date: 2002-05-02
Publication date: 2002-11-14
Also published as: CZ11323U1; EA004751B1; EP1435133A1; EA200301086A1

Abstract

For switching of electromagnetic signals of a field of decametre up to centimetre waves, there is designed an electronic relay comprising at least two branches with a common node, each branch (X1, X2) being furnished with a dipole (A) having at least one diode (7) and being connected in series through a series capacitor (2) with a lowpass frequency LC-filter, the series capacitor (2) having a capacity value at least five times higher than a transition capacity of the diode (7). The dipole (A) is further connected to a source of a first control voltage (U¿1?), while a source of a second control voltage (U2) is connected between an input and an earth terminal (5) of the low-frequency LC-filter. The applied network capacity element is connected to the earth terminal (5) and comprise a diode (7) having a threshold frequency lower than the highest switched frequency. Preferably the earth terminal (5) of the low-frequency LC-filter is connected to the ground via a grounding capacitor (6) having a capacity the value of which is at least five times higher than a transition capacity of the diode (7) of the low-frequency LC-filter.

Description

SWITCHING ELECTRONIC RELAY

Technical Field The invention relates to a switching electronic relay, especially to a relay for switching of electromagnetic signals of a field of decametre up to centimetre waves, the electronic relay being furnished with at least one lowpass frequency filter of a T-network type of at least second order and/or a Pl- network of at least second order, the lowpass frequency filter being equipped with at least one semiconductor diode.

Background of the Invention

In the field of frequencies ranging higher than units of megahertz, especially in the field of frequencies applied for TV broadcasts, for switching of selected frequency bands there are used either special mechanic relays with a low capacity of switching contacts or special electronic relays, with switching elements being provided for by diodes of a PIN type or high frequency transistors of GaAs FET type or by lowpass frequency filters of a T-network or a Pl-πetwork type of at least second order, the networks having semiconductor diodes as a capacity element. By mechanic relays high requirements put on mechanical design with respect to desired negligible contact capacity for operation in the UHF range result in high costs. Electronic relays with PIN type diodes or high frequency transistors of GaAs FET type require high manufacture accuracy and strict compliance with required technology. All such requirements result again in high costs. Switching relays equipped with low frequency T-network or Pl-network type filters manifest rather narrow frequency band in the range from hundreds ot MHz up to units of GHz. frequencies. It is an object of the invention to design a switching electronic relay operating in a very wide wave-length range from decametres up to centimetres. Disclosure and Object of the Invention

The said object is achieved by a switching electronic relay furnished with at least one lowpass frequency filter of a T -network type of at least second order and/or of a Pl-network of at least second order, the lowpass filter being equipped with at least one semiconductor diode, the relay in accordance with the present invention comprising at least two branches with a common node, each branch being furnished with a dipole having at least one semiconductor diode and being through a series capacitor connected in series with a lowpass frequency LC-filter, the series capacitor having a capacity value at least five times higher than a transition capacity of the diode, the dipole being further connected to a source of a first control voltage, while a source of a second control voltage is connected between an input and an earth terminal of the lowpass frequency LC-filter, provided the applied network capacity element, is connected to the earth terminal and comprise a diode having a threshold frequency lower than the highest switched frequency. Further in accordance with the present invention the earth terminal of the lowpass frequency LC-filter can be connected to the ground via a grounding capacitor having a capacity the value of which is at least five times higher than a transition capacity of the diode of the lowpass frequency LC-filter. Still further in accordance with the invention the common node of the two branches can be connected to the first switch terminal via at least one semiconductor diode. The switching relay according to the invention allows for operation with signals the frequencies of which range from units of MHz up to GHz, such an operation being possible by means of simple and reliable technical means without any moving mechanical parts.

Brief Description of the Drawings

The invention shall be further illustrated by way of examples presented in the accompanying drawings, in which Fig. 1 illustrates a principle circuit diagram of the relay, Figs 2, 3 and 4 show preferred embodiments of a block A according to Fig. 1. Figs 5, 6 and 7 present several preferred embodiments of a block B according to Fig. 1. Fig. 8 offers a connection of a multi-pole relay, where branches X¹ and X² are arrays according to Fig. 1. On Fig. 9 there is shown a four-pole relay with branches X¹ and X² according to Fig. 1. Fig. 10 illustrates a preferred embodiment of a double-pole relay.

Description of Preferred Embodiments

Referring to Fig. 1, there is shown a two-pole switching relay having two mutually identical branches X¹, X which are connected to a common first switching terminal 1 Both the first branch X¹ and the second branch X² are provided with a series combination of a dipole A and a triple-pole B having a series capacitor 2 connected between the both units. The series capacitor 2 has a capacity the value of which is at least five times higher than a value of a transition capacity of the semiconductor diode 7 of the lowpass frequency LC-filter. The dipole A is through a first load resistor 3 connected to a source of a first control voltage U-i. The triple-pole B is connected to a source of a second control voltage U₂, the second control voltage U2 being connected through a second load resistor 4 in-between an input and an earth terminal 5 of the triple-pole B. The earth terminal 5 is connected to a ground by means of a grounding capacitor 6, the capacity value of which is at least five times higher than a value of a transition capacity of the semiconductor diode 7 of the lowpass frequency LC-filter. The grounding capacitor 6 may be omitted. The first load resistor 3 and/or the second load resistor 4 may be replaced by an inductive load, both load resistors 3,4 may even have a zero value. The dipole A is performed by at least one semiconductor diode 7 having a threshold frequency value lower than the value of the highest switched frequency, the semiconductor diode 7 being connected in any conductance direction, as seen from Figs. 2, 3 and 4. As the triple-pole B there is used a lowpass frequency LC-filter of a type of a T-network of at least second order and/or a Pl-network of at least second order. A capacity element of the filter comprises a semiconductor diode 7 having a threshold frequency value lower than the value of the highest switched frequency. Figs. 5 and 6 show embodiments of the lowpass frequency LC-filter furnished with a T-network of a second order, the network having two inductors 8 the common node of which is through a semiconductor diode 7 connected to the earth terminal 5. The embodiments presented in Figs. 5 and 6 differ from each other only by a polarity of the semiconductor diode 7 connection. An output of the lowpass frequency LC-filter represents an output of the respective first branch X¹ or the second branch X² of the switching relay, the branch output being equipped with a second switching terminal 10, which provides for a connection to a continuing line. Fig. 7 offers a similar connection of a lowpass frequency LC-filter furnished with a T-network of a fifth order.

The first switching terminal I and the second switching terminal 10 may be mutually interchanged. In a case when a switched signal is connected to the first switching terminal I, then a load is connected to the second switching terminal 10 and vice versa. From the basic two-pole interconnection of the relay in question there are derived further embodiments. As seen from Fig. 8 a multi-pole relay may be easily constructed by a multiple parallel combination of above described branches X¹, X². The number n of individual relay poles corresponds to the number of applied branches _X¹ , X², .... , Xⁿ. Another possibility, as illustrated on Fig. 9, is presented by the embodiment where the common nodal point of the first and the second branches X¹, X² is connected to the first switching terminal I through further dipole A, the construction of which is similar to the one described above for each of the individual branches X¹ , X². Such an array may be also used for construction of multi-pole relays.

The relay according the invention operates in a mode described as follows. A switched signal passes through only one of the two branches X¹, X². In a case when the signal is to pass through the first branch X¹, the first control voltage Ui applied on a dipole A of the first branch X¹ shall be as high as to keep the respective semiconductor diode 7 in a conductive state and the said signal passes through nearly without any attenuation, while the first control voltage Ui applied on a dipole A of the second branch X² shall be of a value to keep the respective semiconductor diode 7 in a non-conductive state and the signal passes highly attenuated. Simultaneously the second control voltage U₂ shall be of a value to keep the respective semiconductor diode 7 of the triple-pole B of the first branch X¹ in a non-conductive state and the said signal passes through nearly without any attenuation, while the second control voltage U2 applied on the triple-pole B of the second branch X² shall be of a value to keep the respective semiconductor diode 7 in a conductive state so the signal passes through the second branch X² highly attenuated. If a signal is to pass only through the second branch X², the dipoles A and the triple-poles B shall be in opposite operation modes as described above.

Fig. 10 shows a practical wiring diagram of a double-pole switching relay constructed in accordance with the invention. The said relay comprise the first and the second branches X¹, X² the common node of which is connected to the first switching terminal 1. A dipole A, featuring two semiconductor diodes 7 in a serial combination, is through a series capacitor 2 connected to a triple-pole B, which is provided with a T-network of a fifth order as shown on Fig. 7. The series capacitor 2 is by-passed by a serial combination of two load resistors 3,4 with an output from their nodal point. The applied T-network comprise a serial combination of three inductors 8, both nodes of adjacent inductors 8 being through a semiconductor diode 7 connected to the earth terminal 5. A source of control voltage U₀ is connected between the nodal point of the two load resistors 3,4 and the common node of the first and the second branches X¹, X².

The operation of this relay arrangement is performed in such a way, that applying a constant control voltage U₀ at the nodal point of the two load resistors 3,4 of the first branch X¹ and a zero voltage at the nodal point of the load resistors 3,4 of the second branch X² the first branch X¹ shall be in a non-conducting state and no signal shall pass through, while the second branch X² shall be in a conducting state and therefore a signal shall pass. On the contrary, when applying a zero voltage at the nodal point of the load resistors 3,4 of the first branch X¹ and a constant control voltage U₀ at the noda\ point of the load resistors 3,4 of the second branch X² the first branch X¹ shall be in a conducting state, thus allowing for signals to pass tthhrroouugghh,, wwhhiillee tthhee sseeccoonndd bbrraarnch X² shall be in a non-conducting state blocking signals to pass through.

Industrial applications

The present invention is designed for equipment for an individual and a community reception of terrestrial or satellite TV signals.

Claims

C L A I M S

1. Switching electronic relay, especially to a relay for switching of electromagnetic signals of a field of decametre up to centimetre waves, the relay being furnished with at least one frequency filter of T-network type of at least second order and/or Pl-network of at least second order, the lowpass filter being equipped with at least one diode, characterised in, that it comprise at least two branches with a common node, each branch (X¹,X²) being furnished with a dipole (A) having at least one semiconductor diode (7) and being via a series capacitor (2) connected in series with a lowpass frequency LC-filter, the series capacity (2) being of a capacity at least five times higher than a transition capacity of the diode (7), the dipole (A) being further connected to a source of a first control voltage (U-i), while a source of a second control voltage (U₂) is connected between an input and a ground terminal (5) of the lowpass frequency LC-filter, provided the applied filter capacity element is connected to an earth terminal (5) and comprise a semiconductor diode (7) having a threshold frequency lower than the highest switched frequency,

2. Switching electronic relay according to claim 1, characterised in, that the earth terminal (5) of the lowpass frequency LC-filter is connected to the ground via a grounding capacitor (6) having a capacity the value of which is at least five times higher than a transition capacity of the diode (7) of the lowpass frequency LC-filter.

3. Switching electronic relay according to claim 1 or 2, characterised in, that the node of two branches (X¹,X²) is connected to a first switching terminal (1) via at least one diode (7).