Variable delay dielectric filled waveguide

Abstract

An electronic variable delay device includes a dielectric waveguide section formed of two or more layers, with gaps formed between the layers. A control element is arranged to adjust a size of at least one of the gaps, where the control element includes at least one piezoelectric, electroactive material, or mechanical position control. A first matching launch section is disposed adjacent a first end of the dielectric waveguide section, and a second matching launch section may be disposed adjacent a second end of the first dielectric waveguide section.

Description

[0001] VARIABLE DELAY DIELECTRIC FILLED WAVEGUIDE

[0002] CROSS REFERENCE TO RELATED APPLICATIONS

[0003] This patent application claims priority to U.S. Provisional Patent Application Ser. No. 63 / 536,551 filed September 5, 2023 entitled "Variable Delay Dielectric Filled Waveguide", the entire contents of which are hereby incorporated by reference.

[0004] TECHNICAL FIELD

[0005] This patent application relates to electronic components, and in particular to a variable delay element.

[0006] BACKGROUND

[0007] International Patent Publication WO2016153459 Al describes a passive electronic scanning array based on a Dielectric Traveling Wave Array (DTWA) technology that uses micro-actuated control of a waveguide transmission medium. The waveguide may be formed from dielectric material layers with gaps between the layers. A control element is also provided to adjust a size of the gaps. The control element may be, for example, a piezoelectric, electroactive material or a mechanical position control. Such gaps may further be used to control the beamwidth and direction of the array.

[0008] U.S. Patent US-2020326607-A1 describes a scanning Dielectric Travelling Wave Array (DTWA) device suitable for use as a wideband, tunable, two-dimensional beamformer. The device is formed from a set of planar waveguides, elongated waveguide sections and / or progressive delay layers. International Patent Publication WO-2018144801-A1 describes a waveguide formed of two or more dielectric control layers. A varactor layer provides control over the propagation constant, in turn permiting the waveguide to act as a steerable antenna having a controllable beam direction.

[0009] SUMMARY OF PREFERRED EMBODIMENTS

[0010] In selected implementations, an electronic device that provides variable delay includes a dielectric waveguide section formed of two or more layers, with gaps formed between the layers. A control element is arranged to adjust a size of at least one of the gaps, where the control element includes at least one piezoelectric, electroactive material, or mechanical position control. A first matching launch section is disposed adjacent a first end of the dielectric waveguide section, and a second matching launch section may be disposed adjacent a second end of the first dielectric waveguide section.

[0011] The resulting device may be further described as a two-port, waveguide-based delay device based on a dielectric-filled, passive waveguide. The resulting device is bi-directional, and scalable over frequency. A matching launch section is provide at each of the waveguide with a variable dielectric filled middle section with reconfigurable gap(s). The matching section can be tailored to implement desired system impedance requirements. The matching section may further have dielectric constants that follow a gradient. The variable middle section may have reconfigurable gaps controlled with electromechanical actuation. The actuation may be via piezoelectric or linear actuators or some other electromechanical device.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] These and other features of this invention are further understood from the description that follows and the accompanying drawings.

[0014] FIG. 1 is a schematic view of an example delay device.

[0015] FIG. 2 is a schematic view of another example delay device.

[0016] FIG. 3 is a schematic view of still another example delay device.

[0017] FIGS. 4A and 4B are isometric and front assembly views of the example device of FIG. 1.

[0018] FIGS. 5A, 5B and 5C are isometric, front and top view views of a casing bottom part.

[0019] FIGS. 6A, 6B and 6C are isometric, front and top view views of a casing middle part.

[0020] FIGS. 7A, 7B, 7C and 7D are isometric, front, top and side view views of a top plate.

[0021] FIGS. 8A, 8B, 8C and 8D are isometric, front, top and side view views of a first dielectric piece.

[0022] FIGS. 9A, 9B, 9C and 9D are isometric, front, top and side view views of a second dielectric piece.

[0023] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] An example waveguide based delay device 100 is shown in FIG. 1. This configuration is designed to provide variable delay in nanoseconds, without discrete steps. The device 100 includes a dielectric filled variable delay middle section 110. Waveguide launch sections 120 located on each end of the middle section 110 provide matching between respective input ports 125 and the variable delay middle 110 section. The degree of match can be tailored to be a required impedance for what other components the delay device 100 may be coupled to.

[0025] The variable delay middle section 110 is a dielectric filled waveguide formed of two or more planar dielectric material layers 130 with one or more gaps 140 between them. The size of the gaps 140 may be reconfigurable, allowing for control of the effective dielectric constant of the middle section 110 and thus control of the group delay. The variable delay middle section 110 can have more than one gap 140. The dielectric constant of the material(s) used to implement the dielectric layers 130 can be tapered or graded in the direction of propagation to provide increased instantaneous bandwidth.

[0026] A control element (not shown in the drawings) is arranged to adjust a size of at least one of the gaps. The control element includes at least one piezoelectric, electroactive material, or mechanical position control.

[0027] The dielectric material layers 130 may be formed from silicon nitride, silicon dioxide, magnesium fluoride, titanium dioxide or other materials suitable for propagation at the desired wavelength of operation. Different material layers may be formed of materials with different dielectric constants to provide the aforementioned gradation.

[0028] The matching launch sections 120 may also be formed of a dielectric material having a different dielectric constant than the dielectric materials used for the middle section 110. As shown in the example of FIG. 1, each matching launch section 120 itself may include an outer portion 150 having different a dielectric constant than an inner portion 160. The device 100 is passive and bi-directional. This is as a result of providing the matching launch sections 120 at each end of the variable delay middle section 110.

[0029] The device 100 may typically be enclosed in a metal or other conductive housing.

[0030] In some configurations, such as that shown in FIG. 2, the air gap(s) may be extended so that the matching launch sections 120 each include a first air gap 140-1 within inner portion 150 and / or second air gap 140-2 within outer portion 160. These air gaps 120-1, 120-2 may be larger in size than the air gap(s) 120 in the center feed section.

[0031] In the example of FIG. 2, the dielectric constant of the material in the middle secton 110 may be 100, the dielectric constant of the inner portion 150 of the matching sections may be 70, and the dielectric constant of the outer portion 160 of the matching sections may be 50.

[0032] In this implementation there may be "legs" or "pins" of dielectric-100 material of middle section 110 that protrude through the walls of the waveguide. This better enables actuation of the middle section 110, while still allowing for variable air gaps 120 above and below the dielectric portions 130.

[0033] An Ansys HFSS computer model of the example of FIG. 2 was generated where the overall dimensions of the device 100 were approximately Sin wide, 0.28in tall and 4.3in long. The length of the dielectric-50 outer portion 160 in the model was 0.421in, the length of dielectric- 70 inner portion 150 was 0.48in, and the length of the dielectric-100 middle portion was 2. Sin. The modeled device provided a change in delay in a range around 0.84ns when operating at L band (1030-1090MHz).

[0034] FIG. 3 shows how the device may be configured with two or more taps or ports that are spaced along the length of the middle portion 110. Such a multiple port device may be used as a beamformer or in other applications. Here a series of conductive probes 300 are placed in a series of cavities 310 located above the variable delay middle section 110. A coupler layer 330 may be utilized to assist with allowing energy to leak out from the variable delay section. The coupler layer 330 may use riblet type directional coupler elements as part of probes 300 that can further assist with tapering the characteristics of the delay device.

[0035] FIGS. 4A and 4B are, respectively, isometric and front assembly views of the example device of FIG. 1. The assembly includes a top plate 401, casing middle 402, casing middle 402, first dielectric piece 403, second dielectric piece 404 and casing bottom 405. This particular implementation is a simple L-Band instantiation with a pair of unitary dielectric pieces 403, 404 that combine the matching and middle variable sections.

[0036] Those of skill in the art will understand the dimensions shown and other parameters are examples only, and the operating characteristics will change depending the waveguide dimensions, dielectric constants, gap sizes, and other configuration details.

[0037] FIGS. 5A, 5B and 5C are isometric, front and top view views of the casing bottom part. It may be formed of a metal such as aluminum.

[0038] FIGS. 6A, 6B and 6C are isometric, front and top view views of the casing middle part. It is also formed of a metal such as aluminum.

[0039] FIGS. 7A, 7B, 7C and 7D are isometric, front, top and side view views of a top plate. It is also formed of a metal such as aluminum.

[0040] FIGS. 8A, 8B, 8C and 8D are isometric, front, top and side view views of a first dielectric piece. This piece may be formed of a material having a dielectric constant of 100. It is configured to provide adjustability via, for example, mechanical or piezoelectric actuation, to control the size of a gap between it and the second dielectric piece.

[0041] FIGS. 9A, 9B, 9C and 9D are isometric, front, top and side view views of the second dielectric piece. It may be formed of a material having a dielectric constant of 100. It is typically not actuated and thus remains fixed.

[0042] Although not shown in the figures, it is also understood that a controller is configured to select which of the modes of operation for the device is implemented at a given point in time. The controller may be implemented by one or more of a hard wired logic circuit, Field Programmable Gate Array (FPGA), Application Specific Integrated Circuit (ASIC), programmed data processor, any combination thereof.

[0043] For example, the spacing between air gap(s) can be set using an electronic circuit with fixed logic, a circuit that implements a look up table or a programmed processor that provides feedback. For example, the control element may be a programmed processor that provides closed loop control of the air gaps using various input sensors to further compensate for temperature, vibration, and other environmental conditions.

[0044] If any of these implementations uses a stored program to implement the logic, the embodiments may comprise or utilize special purpose or general-purpose computers including computer hardware, such as, for example, one or more processors and system memory. These also include physical and other computer-readable media for carrying or storing computerexecutable instructions and / or data structures. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer system. Computer-readable storage media (devices) include RAM, ROM, EEPROM, CD-ROM, solid state drives ("SSDs") (e.g., based on RAM), Flash memory, phase-change memory ("PCM"), other types of memory, other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other similarly storage medium which can be used to store desired program code in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. Transmission media include electromagnetic signals and carrier waves.

[0045] Computer-executable instructions may include, for example, instructions and data which, when executed by a processor, cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language or source code. Therefore, the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is, therefore, indicated by the appended claims rather than by the foregoing description.

Claims

CLAIMS1. A variable delay apparatus comprising: a dielectric waveguide middle section formed of two or more layers, with one or more air gaps formed between the layers; a control element arranged to adjust a size of at least one of the gaps, where the control element includes at least one piezoelectric, electroactive material, or mechanical position control; a first matching launch section disposed adjacent a first end of the dielectric waveguide section; and a second matching launch section disposed adjacent a second end of the dielectric waveguide section.

2. The apparatus of claim 1 wherein the matching launch sections are formed of a dielectric material having a different dielectric constant than a dielectric material used for the middle section.

3. The apparatus of claim 1 wherein each matching launch section comprises an outer portion having different a dielectric constant than an inner portion.

4. The apparatus of claim 1 wherein the air gap(s) extended into the matching launch sections.

5. The apparatus of claim 1 further comprising two or more taps spaced along the middle portion.

6. The apparatus of claim 5 wherein the taps each comprise a conductive probe disposed within a cavity.

7. The apparatus of claim 6 wherein the taps additionally comprise a coupler element disposed above the middle section.

8. The apparatus of claim 1 wherein the dielectric material layers are formed from silicon nitride, silicon dioxide, magnesium fluoride, titanium dioxide or other materials suitable for propagation at a desired wavelength of operation.

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