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Power-Divider-Networks with Integrated Antennas on Multilayer LTCC
a German BMBF/DLR Project (FKZ 50 YB 0007)

Partners References

A German BMBF/DLR project (Oct. 00 - Dec. 02): The LTCC activities of the KANSAS project have been continued in EASTON: Buried power distribution networks in multilayer LTCC have been development. The main component of each distribution network is the Wilkinson power divider with a buried screen printed resistor. An other important part of the project was the LTCC-RF-Benchmarking, where different LTCC materials have been tested and compared up to 40 GHz under equal conditions.

A multilayer power divider network module and a circularly polarized patch-antenna for 20GHz have been developed for space applications. The demonstrator circuits exhibit the advantages of the multilayer LTCC technology: Two divider networks are stacked on top of each other within the multilayer ceramic. Shielded stripline waveguides have been designed to minimize cross-talk. This has been evaluated with test patterns in an early stage of the project. Buried Wilkinson divider and transitions from one waveguide to another have been optimised to achieve a compact and reliable module. The patch antenna is also fed by inner waveguides and optimised transitions.

An RF benchmark has been initiated to compare the properties of commercial LTCC materials up to 40GHz. Worldwide ceramic tape and conductor paste suppliers as well foundry services supported the RF benchmark by supplying material or manufacturing for the test coupons. RF measurements and evaluation have been performed by IMST.

Power Divider Network
2 Wilkinson power divider networks (1-to-4) buried in LTCC and 4 microstrip (MS) through lines on top of the circuitry have been designed in one compact mulitlayer module for space applications at 20GHz. The figure below shows an exploded view of the ground (green) and signal (yellow) layers. Via connections have been eliminated to simplify the graphic. The input ports of the 2 divider networks are on the left hand side of the module in the same level. All 12 output ports (4 for each divider network and 4 for each microstrip through line) are in the rear of the picture, while the 4 MS-line input ports can bee seen in the foreground. Each network consists of 3 Wilkinson power dividers, which have been optimized with the in-house EM-simulation tool EMPIRE. The final divider module is illustrated in in the photohraph inside a DISPAL housing. (further results: see References or Examples/Dividers)

Power divider networks in DISPAL housing

Exploded view of buried dividers in LTCC


The goal of this workpackage was to compare the RF properties of different LTCC material systems. Test patterns have been designed for a common layout. Microstrip (MS) and stripline (SL) ring resonators have been chosen to characterize the effective (MS) and relative (SL) permittivity, the quality factor and the line losses of the LTCC substrates. The conductor line width is equal for each LTCC system to ensure that the results are comparable. The substrates' heights vary depending on the dielectric constants and the available standard tape thickness'. The layout files have been offered to several LTCC suppliers and foundry services for manufacturing the parts. IMST has performed the characterization and evaluation. The MS patterns have been tested up to 40GHz and the SL parts up to 25GHz. The following companies have contributed to this RF-benchmarking initiative: (further results: see References)

  • DuPont 951 (Ag + Au): TU-Ilmenau (Germany), IMST (Germany)
  • DuPont 943 (Ag + Au): VTT (Finland), MSE (Germany)
  • Ferro A6M (Au): Kyocera Vispro (USA)
  • Ferro A6S (Ag): Kyocera Vispro (USA)
  • Samsung TCL-6A, TCL-7A (Ag): Samsung (Korea)
  • Nikko Ag-3 (Ag): Nikko (Japan)

Front view of test tile (DuPont 943)

Back view of test tile (DuPont 943)


Patch Antenna for Circular Polarization
The goal of this workpackage was to investigate suitable antenna patches for linear and circular polarization on multilayer LTCC substrates. The setup for both circuits is illustrated in the grahics below. The linear polarized patch in microstrip configuration is fed by a buried stripline (in blue) and is connected with a filled via. Ground to ground via chains are shielding the feeding line. The circular polarization is achieved by feeding the rotated patch from 2 buried striplines. The signals on the striplines have a phase difference of 90-degree, coming from a branch-line coupler. The E-field of the feeding circuitry and the circular polarization of the far field is illustrated in the pictures below. The 3D field simulation and the animation has been made with IMST's Finite Difference Time Domain simulation tool EMPIRETM. (further results: see References)

Circular polarization of simulated E-field


Project period:
Oct. 2000 - Dec. 2002
Project ID:
Partners Country Description
DLR DE German Space Agency (Bonn): Project Coordinator
IMST GmbH DE Microwave circuit design and characterisation
Technical University Ilmenau DE LTCC prototyping; microwave components design
TESAT Spacecom DE Supplier of satellite technology


# References
WWW DLR Internet Site
Flyer LTCC-RF-benchmark
[25] Technologies for reliable Power Distribution Networks in SAR Earth Observation and Multimedia Communication Satellites
[19] Ka-Band Power-Distribution Networks on Multilayer LTCC for Broadband Satellite Multimedia Applications
[18] Vergleichstest verlustarmer LTCC-Systeme bis 40 GHz
[17] Highly Integrated Power Distribution Networks on Multilayer LTCC for Ka-band Multiple-Beam Phased Array Antennas
[15] Multilayer LTCC-Module für HF-Anwendungen
[12] RF-Benchmark up to 40 GHz for various LTCC Low Loss Tapes


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