R & D projects
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RApid manufacture of Microwave and Power modules
a European Brite Euram III Project (BE-97-4883)

Partners References Irish Coffee

The objective of the RAMP programme was to develop an innovative technology platform incorporating a low temperature co-fired ceramic (LTCC) system for use at frequencies up to 40GHz and expansion matched duplex metal-metalloid alloy (DMMA) of high thermal conductivity. The results of the project have been demonstrated with a number of ambitious circuits and modules, e.g. a 4x4 patch antenna for 24GHz ISM-band applications or an entire 26GHz point-to-multipoint transceiver module in multilayer LTCC. This technology development has proven its benefits for RF and microwave applications due to its high degree of integration and other material and electrical properties. It results into a low cost technology for reliable applications, which is of specific advantage for Small and Medium Enterprises (SME).

Test Coupons

IMST's contribution to this European consortium has started with a comparison of different LTCC material systems and its performance in microwave applications. Ring-resonators and meander lines have been designed on the core component substrate to determine losses and conductivity of DuPont's 951 and Ferro's A6M system. The A6M has shown excellent microwave performance and so it has been utilised to optimise and characterise basic structures like waveguides, transitions and feedthrus.

Test Coupon with waveguides and transitions

Test Coupon with MMIC integration and transitions


Circuits and Antennas

In the next project phase active and passive components have been developed for this LTCC environment: MMIC integration, multiplier development and bandpass filter designs have been carried out and investigated in details. In a parallel task a planar patch antenna has been designed for the 24 GHz ISM-band. The innovation of this work was the feeding concept of the patches: The power divider network was designed as microstrip network on the bottom side of the LTCC. An aperture coupling through an inner ground plane was utilised to excite the patches on the top side of the ceramic. 2x2 and 4x4 patch arrays with different feeding networks have been manufactured and evaluated with excellent results.

LNA in cavity of LTCC

25GHz BP-filter and multiplyer

24GHz patch antenna


Documentation & Publications

The R&D effort has been documented in a number of progress reports as well as 5 publications on IMAPS and IMS conferences during the project. The most comprehensive paper summarises IMST's experience in the brochure "LTCC - An Introduction and Overview", which comprises the most important basics for LTCC beginners and is highly valuable as reference book for experts. (further info: see References)


LMDS Transceiver

One highlight at the end of the RAMP project was the design, manufacturing and evaluation of an entire front-end module for 26 GHz LMDS (Local Multipoint Distribution Services). Transmit, receive and local-oscillator branches have been integrated into one 5-layer LTCC substrate. 12 MMICs have been mounted into stepped cavities, stripline band-pass filters have been buried into the ceramic layers below DC supply lines, a multiplier and Wilkinson power divider has been realised on LTCC and double-rowed shielding via fences have been included to separate the branches from each other. As a result, a compact and highly integrated module in an aluminium package completed the successful R&D work of the RAMP project.

LMDS transceiver

Multilayer LTCC: cross view of transmit branch

IMST has expanded its LTCC business as a result of the gained skills and experience from the RAMP project. An in-house prototyping line for LTCC components, a seminar session for customers, a library for ceramic multilayer components and a wider range of circuit and antenna development services are the main achievements from this R&D effort. In the meantime IMST is a worldwide established institution in the field of multilayer ceramic for microwave communication and sensor applications.


Project period:
Oct. 1998 - Sept. 2001
Project ID:
Partners Country Description
Marconi Caswell Technology GB Microwave module design and build; processor of DMMA and LTCC; metallurgical joining; microwave end user
Thales Microelectronics F Developer of LTCC processes for rapid and lowcost manufacture
IMST GmbH DE Modelling, design and characterisation of 3D microwave circuits
Hywel-Connection NL Manufacturer end-user of DMMA/ceramic electric heaters andpower modules used in current regulators
TNO NL Developer of joining techniques. Characterisation of materialsand evaluation of the joint quality
NMRC IE Simulation to optimise the mechanical and thermal characteristicsof the assembled; electrical and environmental testing


# References
Flyer LMDS-Transceiver
Book LTCC - An Introduction an Overview
[13] Point-to-Multipoint Transceiver in LTCC for 26 GHz
[9] Power Distribution Networks in Multilayer LTCC for Microwave Applications
[8] Efficient Band Pass Filter Design for a 25 GHz LTCC Multichip Module using Hybrid Optimization
[7] Investigation of Ring-Resonators on Multilayer LTCC
[6] Planar Antenna Arrays on LTCC-Multilayer Technology
[5] Integration Techniques for MMICs and Chip Devices in LTCC Multichip Modules for Radio Frequencies
[4] Interconnects and transitions in Multilayer LTCC Multichip Modules for 24 GHz ISM-Band Applications
[2] Design of Passive Components for K-Band Communication Modules in LTCC Environment


Irish Coffee (Cork, IE, April 2000)

measure of whiskey (Jamesons), 1 teaspoon of sugar, coffee, lightly whipped cream (no added sugar)

"Put whiskey and sugar in the glass, leaving the spoon in the glass. Add the coffee (this is so the glass does not break) stir until sugar is dissolved (not dissolved cream will sink). To add the cream take a little at a time with a hot spoon. Keep a jug of hot water and keep the teaspoon in it. This enables the cream to slide off easily."
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