DE102010014864A1 - Waveguide connection for antenna panels of e.g. planar active phased array antenna, for space application, has waveguides comprising co-ordination elements, in which phase alignment of transit phase is distinguished from antenna panel - Google Patents

Abstract

The connection has a waveguide element (100) and another waveguide element aligned together in an unfolded state of an antenna system. The waveguide elements comprise a set of choke flange waveguides (101-103), which are oriented around 90 degrees to each other. A signal channel is provided by the waveguides element pairs. The choke flange waveguides comprise co-ordination elements (141-143) i.e. co-ordination screws, in which a phase alignment of a transit phase i.e. insertion phase, is distinguished from an antenna panel.

Description

The invention relates to a non-contact, tunable waveguide connection for an antenna system comprising a plurality of mutually movable antenna panels, the waveguide connection a first waveguide element coupled to a first antenna panel and a second waveguide element coupled to a second antenna panel adjacent to the first antenna panel , includes. The first and second waveguide elements adjoin one another in a deployed state of the antenna system. The invention further relates to an antenna system comprising a plurality of mutually movable antenna panels with a waveguide connection.

In antenna systems intended for space applications, the antenna panels, initially folded for transport, are deployed in orbit. It is necessary to signal technically connect the individual, adjacent antenna panels with a connection component.

An example of such an antenna system is the so-called "Sentinel-1 SAR Antenna Subsystem (SAS)" for the Sentinel-1 mission. The antenna system is a planar, phased array antenna ("Planar Active Phased Array Antenna") operating in the C band (5.405 GHz) with a frequency bandwidth of 100 MHz. The antenna system, when deployed, has a total size of 12.3m x 0.84m and is formed by a central panel mounted at the top of a spacecraft and two side antenna wings on two adjacent sides of the spacecraft. The central panel is equipped with two so-called SAS plates (tiles), whereas the two antenna panels of each side wing each have three SAS plates. Overall, the antenna system thus has 14 identical plates: six SAS plates on the right antenna wing, two SAS plates on the central panel and six SAS plates on the left side wing. Each of the SAS disks has all the necessary functions required for beam shaping and steering.

• – Signalausstrahlung und Empfang (WG-Assy),
• – Hochleistungsverstärkung eines verteilten Sendesignals (EFEs, TAAs),
• – rauscharme Verstärkung eines verteilten Empfangssignals mit LNA-Schutz (EFEs),
• – Signal- und Leistungsverteilung (gemeinsame Einspeisung, Leistungswandlung) (RFDN),
• – Phasen- und Amplitudensteuerung einschließlich Temperaturkompensation (EFEs über TCU),
• – interne Kalibrierschleife,
• – Bereitstellung eines Entfaltungsmechanismus einschließlich Niederhalter und Freigabe,
• – Bereitstellung der mechanischen Antennenstruktur.

Such an antenna system comprises the following basic functions:

• - signal transmission and reception (WG-Assy),
• High power amplification of a distributed transmission signal (EFEs, TAAs),
• Low-noise amplification of a distributed reception signal with LNA protection (EFEs),
• - signal and power distribution (common supply, power conversion) (RFDN),
• - phase and amplitude control including temperature compensation (EFEs via TCU),
• - internal calibration loop,
• - providing a deployment mechanism including hold-down and release,
• - Provision of the mechanical antenna structure.

A signal distribution network (RF-Distribution Network, RFDN) in transmit mode distributes the signals from a SAR subsystem (SAR Electronic Subsystem, SES) to the antenna boards, i. H. to the input terminals of a Tile Amplifier Assembly (TAA), with a good phasing. At the SAS disk level, the RFDN distributes the transmit signals from an output of the TAA amplifier unit to Electronic Front End (EFE) modules with good phasing. For reception, the signal distribution network RFDN combines the received signals in the reverse direction.

• – ein sog. Azimuth Plane Distribution Network (APDN) für die Signalverteilung auf Ebene der Antennenpaneele,
• – ein sog. Elevation Plane Distribution Network (EPDN) für die Signalverteilung auf SAS-Plattenebene,
• – RF Harness.

The signal distribution network RFDN is made up of the following elements:

• A so-called azimuth plane distribution network (APDN) for the signal distribution at the level of the antenna panels,
• A so-called Elevation Plane Distribution Network (EPDN) for signal distribution at the SAS disk level,
• - RF Harness.

• – Im Sendemodus: Verteilung des Sendesignals von dem SES über die Plattenverstärker zu den EFEs mit einer geringen Phasenvariation zwischen den Ausgangsanschlüssen.
• – Im Empfangsmodus: Kombination der empfangenen Signale von den EFEs über die Platten-Verstärker (Tile Amplifier) in Richtung des SES mit einer geringen Phasenvariation zwischen den verschiedenen Empfangspfaden.
• – Bandpassfilterung im Sende- und Empfangspfad.

The signal distribution network RFDN has the following main functions:

• In transmission mode: Distribution of the transmission signal from the SES via the plate amplifiers to the EFEs with a small phase variation between the output ports.
• - In receive mode: combining the received signals from the EFEs via the plate amplifiers (Tile Amplifier) towards the SES with a small phase variation between the different receive paths.
• - Bandpass filtering in the transmit and receive paths.

At the board level, the signal distribution network's EPDNs include RFDN coaxial cables and power distribution / combiner. At antenna panel level, the APDN includes coaxial cable and power distribution / combiner components in a similar manner.

The signaling connection of the individual antenna panels is done using waveguide connections. In this case, it is necessary to effect a phase adjustment from antenna panel to antenna panel or from signal channel to signal channel. For this purpose, so-called. Tuning screws are used to fine tune the passage phase, but without changing the adaptation to make. To cover a sufficiently large tuning range, several screws are usually necessary. Another possibility, to tune the passage phase, is the use of a so-called "trombone". This is a line piece, which can be changed in length. The use of a trombone requires a contact-type configuration of the waveguide connection, in which the first and second waveguide element are brought into corresponding contact. However, these variants are relatively expensive and unsuitable as a connecting element between the panels. Moreover, trombones can only be used within a panel, as long as it is a waveguide supply network.

It is therefore an object of the present invention to provide a waveguide connection for an antenna system and an antenna system with which a phase adjustment of antenna panel to antenna panel in a simpler manner vornehmbar.

These objects are achieved by a waveguide connection according to the features of claim 1 and an antenna system according to the features of claim 15. Advantageous embodiments result from the dependent claims.

The invention provides a non-contact, tunable waveguide connection for an antenna system comprising a plurality of mutually movable antenna panels, wherein the waveguide connection is a first waveguide element coupled to a first antenna panel and a second waveguide element coupled to a second antenna panel adjacent the first antenna panel , includes. In this case, the first and the second waveguide element adjoin one another in an unfolded state of the antenna system. The first waveguide element comprises a number of first throttle flange waveguides, which are oriented in pairs by 90 ° to each other. The second waveguide element comprises a corresponding number of second throttle flange waveguides, which are oriented in pairs relative to the first throttle flange waveguides by 90 ° to each other. A signal channel is provided by a respective hollow conductor pair of a first and a corresponding second throttle flange waveguide. Each of the first and second Drosselflanschhohlleiter has a feed element, wherein via the feed element, an RF signal is magnetically coupled or decoupled in the respective Drosselflanschhohlleiter. Each of the first and / or second throttle flange waveguides has a tuning element, via which a phase adjustment of the passage phase from antenna panel to antenna panel vornehmbar.

The waveguide connection according to the invention allows the compensation of the phase differences of the number of signal channels in a large range, without significantly changing insertion losses. This has the consequence that the waveguide connection according to the invention operates almost lossless. These functional advantages, but also easier manufacture and handling, result from the combination of the throttle flange waveguides in the first and second waveguide elements, wherein the throttle flange waveguides are oriented in pairs at 90 ° to one another. The 90 ° orientation allows for improved signal decoupling. The additional provision of a feed element and tuning element in each of the choke flange waveguides allows integral tuning of the through-phase waveguide connection. By changing the position of the Abstimmelements creates a capacitive component in Speiselementbereich, which changes the phase.

According to an expedient embodiment, the first and the second waveguide element in the unfolded state of the antenna system adjoin one another without contact and aligned to form an air gap. In order to prevent the air gap formed between the first and the second waveguide element from leading to undesirable radiation and losses in the signal path to provide a contactless waveguide connection, according to a further embodiment, the first choke flange waveguides face one another, the flange of the second waveguide element Side of the flange of the first waveguide element are provided with a corrugation. Corrugations are also referred to as choke ring or choker. Conveniently, the corrugation is in the form of a ring. Preferably, the corrugation surrounds each one of the first throttle flange waveguides.

According to a further expedient embodiment, the feed element has a first and a second end, both of which are electrically connected to a waveguide wall of an associated throttle flange waveguide. The feed element forms a "loop" whose ends have the electrical connection to the waveguide wall. The feed element is also referred to as a "feed hook" or "feed sample". The electrical connection of the two ends of the feed element brings EMC advantages (electromagnetic compatibility) with it.

According to a further expedient embodiment, a current fed into the feed element forms a magnetic field around it, whereby an H10 wave can be excited in the associated throttle flange waveguide.

In a further alternative embodiment, the tuning element is arranged above the feed element. This does not change the customization. Only the passage phase is changed over a large area. Especially the insertion loss produced by the feed element and tuning element remains unchanged.

In a further embodiment, no further tuning elements are provided in addition to the tuning of a respective Drosselflanschhohlleiters. As a result, the waveguide connection according to the invention can be formed with the least possible number of elements. This not only reduces manufacturing costs, but also potential sources of error or phasing reconciliation processes are simplified.

In a further embodiment, the tuning elements of a pair of waveguides in the first and the second Drosselflanschhohlleiter are each formed with a predetermined penetration depth. Particularly preferably, the tuning elements of a waveguide pair in the first and the second Drosselflanschhohlleiter are each formed with the same depth of penetration. The arrangement according to the invention allows a large phase adjustment range of the insertion phase, a low degradation with respect to the adaptation (VSWR) and the insertion loss.

According to a further embodiment, the tuning elements are designed as tuning screws, in particular Johansson Tuning Screws.

In a specific embodiment, the number of first and second throttle flange waveguides is three. As a result, the signal channels TX, RX-V and RX-H can be provided and realized in the waveguide connection according to the invention.

Conveniently, the first and second throttle flange waveguides have a rectangular cross-section.

The invention further provides an antenna system comprising a plurality of mutually movable antenna panels with a waveguide connection. In this case, the waveguide connection is configured according to the above description. In particular, the antenna system is intended for use in orbit.

The invention will be described in more detail below with reference to an embodiment in the figures.

Show it.

1a and 1b a perspective view of a first waveguide element obliquely from behind and obliquely from the front,

2 a plan view of a first waveguide element, are removed in the short-circuit plates of the three illustrated Drosselflanschhohlleiter,

3 an enlarged view of a first throttle flange waveguide of the first waveguide element,

4a and 4b a perspective view of a second waveguide element obliquely from the front and obliquely behind,

5 a waveguide connection according to the invention in an arrangement as it would be in an unfolded state of the antenna panels of an antenna system,

6a . 6b and 6c different views of an inventively designed Drosselflanschhohlleiters, from which a concrete realization can be seen.

The 1a and 1b each show in a perspective view a first waveguide element 100 a waveguide connection according to the invention 1 which completely in 5 is shown. This in 1 illustrated first waveguide element 100 is coupled in operation with a, not shown in the figure first antenna panel of an antenna system of a plurality of mutually movable antenna panels. A corresponding second waveguide element 200 that in different perspective representations in the 4a and 4b is coupled to a second, adjacent to the first antenna panel antenna panel in operation. When the antenna system is in a deployed state, the first and second waveguide elements are adjacent 100 . 200 to each other, like this one 5 can be seen.

The antenna panels of the antenna system are folded into orbit during their transport and are deployed in orbit so that the antenna system assumes its final operational shape. The signaling connection of the individual antenna panels takes place in the region of the "interface" of two adjoining antenna panels using the waveguide connection 1 , which the first and the second waveguide element 100 . 200 includes.

The first waveguide element 100 and the second waveguide element 200 limits in the deployed state of the antenna system to form a gap 20 contactless and aligned with each other.

The first waveguide element 100 has in the embodiment three first Drosselflanschhohlleiter 101 . 102 . 103 on, which are oriented in pairs by 90 ° to each other. The throttle flange waveguide 101 . 102 . 103 are called choke flange and have a waveguide wall 107 . 108 . 109 each with a rectangular cross section. At the one respective flange 104 . 105 . 106 opposite side of the waveguide wall 107 . 108 . 109 are so-called short-circuit plates arranged, which close the waveguide on its back.

The second waveguide element 200 has a corresponding number of second throttle flange waveguides 201 . 202 . 203 on, corresponding to the first throttle flange waveguides 101 . 102 . 103 are also oriented in pairs by 90 ° to each other. The waveguide walls of the second throttle flange waveguide 201 . 202 . 203 are with the reference numerals 207 . 208 . 209 characterized. Again, at the respective flange 204 . 205 . 206 opposite ends of the waveguide walls 207 . 208 . 209 closed with shorting plates.

By a respective waveguide pair (see reference numeral 11 . 12 . 13 in 5 ) of a first and a corresponding second throttle flange waveguide 101 and 201 respectively. 102 and 202 respectively. 103 and 303 a respective signal channel is provided. In the waveguide connection shown in the embodiment 1 are used as signal channels, the RF signal branches TX (waveguide pair 11 ), RX-V (waveguide pair 12 ) and RX-H (waveguide pair 13 ) provided.

Since - as already described above - the first and the second waveguide element 100 . 200 in the unfolded state of the antenna system do not touch, could be caused by the resulting between the two waveguide elements gap 20 unwanted radiation and thus losses in the signal path arise. To counteract this, point the flanges 104 . 105 . 106 of the first waveguide element 100 on the flanges 204 . 205 . 206 of the second waveguide element 200 in the operation side facing each corrugation 110 . 111 . 112 in the form of a ring. This is therefore also referred to as choke or choke ring.

By the summary of the three throttle flange waveguides 101 . 102 . 103 respectively. 201 . 202 . 203 in a waveguide element 100 respectively. 200 and a paired arrangement at 90 ° to each other increases the signal decoupling - in addition to the corrugations.

Each of the first and second throttle flange waveguides 101 . 102 . 103 and 201 . 202 . 203 has a feed element 121 . 122 . 123 (see. 2 and 3 for the first waveguide element 100 ) and 221 . 222 . 223 (not visible in the figures for the waveguide element 200 ) as well as a tuning element 141 . 142 . 143 and 241 . 242 . 243 on. This in the perspective views of the 1 and 4 unrecognizable feed element allows magnetic coupling of an RF signal into the respective throttle flange waveguide. The arranged in the interior of the associated Drosselflanschhohlleiter feed elements are each arranged with an outside of the waveguide walls signal feed 131 . 132 . 133 and 231 . 232 . 233 coupled. By means of the signal feeds, there is a transition from a coaxial feed network connected thereto to the choke flange waveguides.

How better off 2 which shows a plan view of the first waveguide element 100 with removed shorting plates showing, are the feed elements 121 . 122 . 123 formed in the shape of a right-angled loop.

3 shows the arrangement of the elements of the throttle flange 101 in an enlarged view. Their first and second ends 124 . 125 respectively. 126 . 127 respectively. 128 . 129 are each electrically connected to the associated waveguide wall 107 . 108 . 109 connected. The electrical connection of the two ends with the associated waveguide wall improves the electrical properties in terms of electromagnetic compatibility (EMC - Electromagnetic Coupling). The feeding elements 121 . 122 . 123 , which are also referred to as a feed hook, allow a magnetic coupling of the voltage applied to the signal input signal. The current, over the respective feed hook 121 . 122 . 123 flows, creating a magnetic field therearound, thereby exciting an H10 wave in the associated throttle flange waveguide.

The tuning of the passage phase via the trained as a screw tuning element 141 . 142 . 143 , which is located directly above the associated feed hook 121 . 122 . 123 located. At this position, a particularly large tuning range can be achieved. In addition, additional tuning elements are unnecessary. The provision of the tuning screws, which are preferably designed as a Johansson tuning screw, provides an integral tuning capability implemented in the respective throttle flange waveguide. This also applies in a corresponding manner to the second waveguide element 200 ,

By screwing in the respective tuning screw creates an additional capacitive share in the region of the associated feed hook, which changes the passage phase. The screwing in of both tuning screws of a waveguide pair 11 . 12 . 13 ensures that a large phase tuning range is obtained and the matching and transmission loss does not to be influenced. By screwing both tuning screws of a respective waveguide pair 11 . 12 . 13 Deteriorations in the adaptation and in the insertion loss are prevented. Only the insertion phase is affected, and this is the effect needed to perform the phasing.

The 6a . 6b and 6c show the relative positioning of the tuning screw 141 to the feed hook (feed element) 121 , In particular, from the sectional views of 6b and 6c it shows that the tuning screw 141 above the feeding element 121 is arranged. The tuning screw 141 is screwed to the desired depth TL, which in practice, for example, should be no more than 4 mm for the Sentinel-1 application. The distance of the center of the tuning screw 141 to the waveguide wall lying in the x-direction 107 is in 6c marked with TD1. With TD2 is the distance of the center of the tuning screw 141 from the lying in the z-direction wall of the waveguide wall 107 characterized. The diameter of the tuning screw is preferably 4 mm, for example for the Sentinel-1 application. For example, TD1 is 4.9mm +/- 0.1mm. For example, TD2 is 19.075 mm +/- 0.2 mm. The waveguide wall 107 Forms a waveguide piece whose length is slightly more than a waveguide wavelength to decay parasitic modes. The transition from the waveguide into the coaxial conductor region is realized by the feed element 121 ,

Be the tuning screws of a respective pair of waveguide 11 . 12 . 13 Achieved to the same depth of penetration, a high performance is achieved, ie a large phase adjustment phase of the insertion phase (insertion phase), a small degradation in the adjustment (VSWR) and the insertion loss (Insertion Loss).

The penetration depth of the tuning screws 141 is determined as follows: First, at least the passing phase of each signal path (signal channel) of each pair of waveguides is measured. The difference between the individual signal channels / signal paths is the variable to be compensated. A reference channel to be matched is set. Subsequently, the passage phase of each signal channel is measured again. During the measuring process, the tuning screws of the signal channel to be tuned are screwed in until the signal channel matches the reference channel.

The waveguide connection according to the invention allows the control of the S ₂₁ phase delay, for example for the Sentinel-1 application in a range of 0 ° to 30 °, whereby the performance of the S ₁₁ and S ₂₁ magnitudes can be maintained. With respect to the S ₁₁ parameter, a 4 mm penetration allows the retention loss to be maintained below -20 dB over a 100 MHz frequency bandwidth. With regard to the S ₂₁ parameter, the effect on insertion loss at a penetration depth of 4 mm is negligibly small. A tuning range of 15 ° can be achieved with a penetration depth of 4 mm.

The waveguide connection thus allows the signal propagation between two adjacent antenna panels. A Johansson tuning screw is a space-qualified microwave tuning element.

LIST OF REFERENCE NUMBERS

1

Waveguide junction

11

Waveguide pair

12

Waveguide pair

13

Waveguide pair

20

gap

100

first waveguide element

101

first throttle flange waveguide

102

first throttle flange waveguide

103

first throttle flange waveguide

104

flange

105

flange

106

flange

107

Waveguide wall

108

Waveguide wall

109

Waveguide wall

110

corrugation

111

corrugation

112

corrugation

121

feed element

122

feed element

123

feed element

124

first end of the feed element 121

125

second end of the feed element 121

126

first end of the feed element 122

127

second end of the feed element 122

128

first end of the feed element 123

129

second end of the feed element 123

131

signal feed

132

signal feed

133

signal feed

141

tuning

142

tuning

143

tuning

200

second waveguide element

201

second throttle flange waveguide

202

second throttle flange waveguide

203

second throttle flange waveguide

204

flange

205

flange

206

flange

207

Waveguide wall

208

Waveguide wall

209

Waveguide wall

221

feed element

222

feed element

223

feed element

231

signal feed

232

signal feed

233

signal feed

241

tuning

242

tuning

243

tuning

TL

Penetration depth of the tuning element

TD1

Distance of the tuning element to the waveguide wall

TD2

Distance of the tuning element to the waveguide wall

Claims (16)

Waveguide connection ( 1 ) for an antenna system comprising a plurality of mutually movable antenna panels, wherein the waveguide connection a first waveguide element ( 100 ), which is coupled to a first antenna panel, and a second waveguide element ( 200 ) coupled to a second antenna panel adjacent to the first antenna panel, the first and second waveguide elements (16) 100 . 200 ) in an unfolded state of the antenna system aligned with each other, wherein - the first waveguide element ( 100 ) a number of first throttle flange waveguides ( 101 . 102 . 103 ), which are oriented in pairs by 90 ° to each other, - the second waveguide element ( 200 ) a corresponding number of second throttle flange waveguides ( 201 . 202 . 203 ) corresponding to the first throttle flange waveguides ( 101 . 102 . 103 ) are oriented in pairs by 90 ° to each other, - by a respective waveguide pair ( 11 . 12 . 13 ) of a first and a corresponding second throttle flange waveguide ( 101 . 102 . 103 . 201 . 202 . 203 a signal channel is provided, - each of the first and second throttle flange waveguides ( 101 . 102 . 103 . 201 . 202 . 203 ) a feed element ( 121 . 122 . 123 . 221 . 222 . 223 ), wherein via the feed element ( 121 . 122 . 123 . 221 . 222 . 223 ) an RF signal magnetically into the respective throttle flange ( 101 . 102 . 103 . 201 . 202 . 203 ) can be coupled in or out, and - each of the first and / or second throttle flange waveguides ( 101 . 102 . 103 . 201 . 202 . 203 ) a tuning element ( 141 . 142 . 143 . 241 . 242 . 243 ), via which a phase adjustment of the passage phase of antenna panel to Antennenpannerel is vornehmbar. Waveguide connection according to claim 1, characterized in that the first and the second waveguide element ( 100 . 200 ) in the deployed state of the antenna system to form a gap ( 20 ) borderlessly and aligned with each other. Waveguide connection according to claim 1 or 2, characterized in that the first throttle flange waveguides ( 101 . 102 . 103 ) on one, the flange of the second waveguide element ( 200 ) facing side of the flange of the first waveguide element ( 100 ) with a corrugation ( 110 . 111 . 112 ) are provided. Waveguide connection according to claim 3, characterized in that the corrugation ( 110 . 111 . 112 ) is formed in the form of a ring. Waveguide connection according to claim 3 or 4, characterized in that the corrugation ( 110 . 111 . 112 ) each one of the first throttle flange ( 101 . 102 . 103 ) surrounds. Waveguide connection according to one of the preceding claims, characterized in that the feed element ( 121 . 122 . 123 . 221 . 222 . 223 ) has a first and a second end, both electrically connected to a waveguide wall ( 107 . 108 . 109 . 207 . 208 . 209 ) of an associated throttle flange waveguide are connected. Waveguide connection according to one of the preceding claims, characterized in that a in the feed element ( 121 . 122 . 123 . 221 . 222 . 223 ) fed a magnetic field around this formed, whereby in the associated Drosselflanschhohlleiter a H10 wave can be excited. Waveguide connection according to one of the preceding claims, characterized in that the tuning element ( 141 . 142 . 143 . 241 . 242 . 243 ) above the feed element ( 121 . 122 . 123 . 221 . 222 . 223 ) is arranged. Waveguide connection according to one of the preceding claims, characterized in that in addition to the tuning element ( 141 . 142 . 143 . 241 . 242 . 243 ) of a respective throttle flange waveguide no further tuning elements are provided. Waveguide connection according to one of the preceding claims, characterized in that the tuning elements of a waveguide pair are formed in the first and the second Drosselflanschhohlleiter each having a predetermined penetration depth. Waveguide connection according to claim 10, characterized in that the tuning elements ( 141 . 142 . 143 . 241 . 242 . 243 ) of a waveguide pair ( 11 . 12 . 13 ) are formed in the first and the second Drosselflanschhohlleiter each having the same depth of penetration. Waveguide connection according to one of the preceding claims, characterized in that the tuning elements ( 141 . 142 . 143 . 241 . 242 . 243 ) are designed as tuning screws, in particular Johansson Tuning Screws. Waveguide connection according to one of the preceding claims, characterized in that the number of first and second throttle flange waveguides ( 101 . 102 . 103 . 201 . 202 . 203 ) is three. Waveguide connection according to one of the preceding claims, characterized in that the first and second throttle flange waveguides ( 101 . 102 . 103 . 201 . 202 . 203 ) have a rectangular cross-section. Antenna system comprising a plurality of mutually movable antenna panels with a waveguide connection, characterized in that the waveguide connection is formed according to one of the preceding claims. Antenna system according to claim 15, characterized in that this is provided and / or designed for use in orbit.

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