RF CROSSOVER APPARATUS FOR MICROWAVE SYSTEMS

Abstract

An RF crossover apparatus provides low transmission and return losses for microwave systems and meets the requirement for the RF signals to leap over each other as in an insulated state. The RF crossover apparatus contains a body produced from ceramic material, at least two RF strips placed inside the body in a way to intersect each other and at least one insulation layer insulating the RF strips placed on the body at least from the external environment. The body produced from ceramic material enables operation on high frequencies and this provides low transmission and return losses. The RF crossover apparatus also contains matching circuits on the tips of the RF strips for the RF strips to be passed to chip devices during use.

Claims

1. A radio frequency (RF) crossover apparatus suitable for a use with microwave systems, comprising at least one body, at least two RF strips transmitting RF signals and placed to intersect each other on the body, and at least one insulation layer, wherein the at least one insulation layer is placed on at least one surface of the body and insulates the RF strips at least from an external environment, and the body is formed of a ceramic material and is configured for an operation in high frequencies.

2. The RF crossover apparatus according to claim 1, wherein the ceramic material is a ceramic based material sintered at low temperatures.

3. The RF crossover apparatus according to claim 1, wherein the body comprises a base part, wherein the at least two RF strips are placed on the base part; and at least one protective part, wherein the at least one protective part is integrated with the base part and extends outwards from the base part, and at least partially covers the at least two RF strips placed on the base part.

4. The RF crossover apparatus according to claim 3, wherein at least one RF strip inside the body does not come in contact with the at least one protective part.

5. The RF crossover apparatus according to claim 4, the at least one RF strip extends towards the at least one protective part at an intersection point of the at least two RF strips.

6. The RF crossover apparatus according to claim 3, wherein the at least one insulation layer is located on a surface of the at least one protective part, wherein surface of the at least one protective part does not face the at least two RF strips.

7. The RF crossover apparatus according to claim 1, wherein the at least one insulation layer comprises at least one perforated transition configured to increase a spectral band and decreasing transmission losses by increasing an insulation between a RF earthing material and the at least two RF strips.

8. The RF crossover apparatus according to claim 1, further comprising a matching circuit, wherein the matching circuit provides transmission to chip devices provided in the microwave systems on tips of the at least two RF strips on the body.

9. The RF crossover apparatus according to claim 8, wherein the matching circuits is configured in a way to provide impedance matching with the chip devices.

10. The RF crossover apparatus according to claim 1, wherein the at least one body includes a plurality of bodies placed on each other.

11. The RF crossover apparatus according to claim 10, further comprising at least one earthing layer on outside facing surfaces of the plurality of bodies for providing equipotential earthing between the plurality of bodies.

12. A method of obtaining an RF crossover apparatus suitable for use in microwave systems according to claim 10, comprising the steps of assembling the plurality of bodies by baking on high temperatures and applying an earthing layer on outer surfaces of the plurality of bodies after the plurality of bodies are assembled.

13. The RF crossover apparatus according to claim 2, wherein the body comprises a base part, wherein the at least two RF strips are placed on the base part; and at least one protective part, wherein the at least one protective part is integrated with the base part and extends outwards from the base part, and at least partially covers the at least two RF strips placed on the base part.

14. The RF crossover apparatus according to claim 5, wherein the at least one insulation layer is located on a surface of the at least one protective part, wherein surface of the at least one protective part does not face the at least two RF strips.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The application of the RF crossover apparatus for a microwave system developed with the present invention is shown in the attached figures for illustration purposes.

[0014] FIG. 1 is the perspective view of the RF crossover apparatus.

[0015] FIG. 2 is the top schematic view of the RF crossover apparatus.

[0016] FIG. 3 is the cross-sectional view of a multilayer structure obtained by using RF crossover apparatuses.

[0017] The parts in the figures are numbered and their references are given below:

TABLE-US-00001 RF crossover apparatus (A) Body (1) RF strip (2) Insulation layer (3) Base part (4) Protective part (5) Matching circuit (6) Earthing layer (7)

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The illustrative embodiments of the RF crossover apparatus (A) are presented in FIGS. 1-3 and is suitable for use in microwave systems and it comprises; at least one body (1), at least two RF strips (2) transmitting RF signals and placed on the body (1) so as to intersect each other and an insulation layer (3) takes place on at least one surface of the body (1) facing the external environment and insulating the RF stripes (2) from the external environment. The body (1) of the RF crossover apparatus contains a base part (4) on which RF stripes (2) are placed and at least one protective part (5) integrated with the base part (4) and extending outwards from the base part (4) in a way to at least partially cover the RF stripes (2) placed on the base part (4). In the preferred embodiment of the invention, at least one of the RF stripes (2) does not have contact with the protective part (5). In a derivative of the preferred embodiment of the invention, the RF stripe (2) intersecting with the RF stripe (2) which does not contact the protective part (5) extends towards the protective part (5) at the intersection point of the RF stripes (2) and in this state, the two RF stripes (2) intersect with an approximately 90 degrees angle. The body (1) containing the base part (4) and protective part (5) in the RF crossover apparatus (A) is produced from ceramic material which enables the RF stripes (2) to operate on high frequencies (i.e. over 30 GHz). In a preferred specific embodiment of the invention, the body (1) is produced from a ceramic material which is low temperature sintered ceramic based (LTCC_Low Temperature Cofired Ceramic). In the preferred embodiment of the invention, the insulation layer (3) takes place on the surface of the protective part (5) which does not face RF stripes (2). The insulation layer (3) contains at least one perforated transition decreasing the transmission losses and increasing the spectral band by increasing insulation between the RF earthing material and RF stripes (2).

[0019] In the preferred embodiment of the invention, RF crossover apparatus (A) also contains matching circuits (6) that provide transmission to chip devices used in microwave systems on the tips of the RF strips (2) on the body (1) base part (4). In the preferred embodiment of the invention, the matching circuits (6) are configured in a way to provide impedance matching with the chip devices.

[0020] Thanks to the subject matching networks (6), operation of the crossover between the RF strips (2) on wide frequency band and low transmission and return losses are obtained in the RF crossover apparatus (A). In addition to all of these, the necessity for an additional matching circuit for the chip devices during applications is eliminated and applications become easier.

[0021] In an embodiment of the invention the RF crossover apparatus (A) contains more than one bodies (1) placed on each other (FIG. 3). In this embodiment of the invention, the bodies (1) are connected together by baking at high temperatures (i.e. over 800 C.) and by this means, a durable and hermetic structure is obtained. In the subject embodiment, there is at least one earthing layer (7) on the outside facing surfaces of the bodies (1) to provide equipotential earthing between the bodies (1). The earthing layer (7) is applied to the external surfaces of the bodies (1) after the bodies (1) are assembled together. In this embodiment of the invention, the insulation layer (3) preferably taking place on the protective layer (5) also provides the insulation between the RF strips in the bodies (1).

[0022] The RF crossover apparatus (A) enables to operate in high frequency thanks to the body (1) produced from ceramic material. In this way, low transmission and return losses are provided. The subject RF crossover apparatus (A) also protects the RF strips (2) against the noise that could be originating from the exter