Multifunctional Micro- & MM-Wave Modules
a German BMBF, VDI/VDE-IT Project
The prototype of a multifunctional LOS (Line of Sight) transceiver module has been developed for a frequency range of 27.5 to 29.5GHz. The highlights of this project are the advanced plastic technology for waveguide components like slotted waveguide antenna, power divider and diplexer, the multilayer PTFE board for intermediate frequency operation as well as the multilayer LTCC technology for the mm-wave module. This project demonstrates in an impressive way the combination and integration of the different technologies into one transceiver module.
The heart of the multifunctional transceiver is the mm-wave module, which consists of the transmit, the receive and the local oscillator circuit. The intermediate frequencies at 4.7 to 6.3 GHz and the LO input frequency at 11.334 GHz are routed through pin connections to the main board, while the RF-transitions are realized by planar to rectangular waveguide transitions (LO = 34 GHz, Tx-Rx = 27.7 to 29.3 GHz). GaAs amplifieres from UMS are mounted on the LTCC substrate. The tripler and the mixer circuits are hybrid solutions, using discret devices mounted in flip-chip technology on the LTCC. The following photographs show details of this module.
As a preparation for the mm-wave module LTCC test ciruits have been desigend and evaluated. A number of different waveguides, transitions from one line to an other, coupled lines, filters, resonators, calibration standards and other test vehicles have been fabricated on the 4-layer Green TapeTM 951 from DuPont with FodelTM gold conductors on the top side of the substrate. The microstrip (MS) and the coplanar waveguide (CPW) circuit topology have been investigated and show promissing results for applications up to 40 GHz. Some examples from these investigations are presented in the following figures:
The IMST was involved in the tasks:
- IF-board and oscillator module
- Components and integration techniques for MM-wave module
- LTCC-multilayer test circuit design and evaluation
- Development of waveguide slot antenna array
- Development of rectangular waveguide components
Figure 1 shows a photo of the transceiver unit. The radom cover has been repleaced, so that the slotted antenna waveguide elements can be seen. Figure 2 depicts a schematic drawing of the module in top view and cross section labled by the main components.
print view
