¹⁾ Dept. for RF and Microwave Techniques, ²⁾ Electronics Technology and Microperipheric Group. Faculty for Electrical Engineering and Information Technology, Technische Universitдt Ilmenau, P.O. Box
100565, 98684 Ilmenau, Germany.

Abstract – We develop a 4Ч4 single-pole multi-throw switch matrix in LTCC technology, for satellite applications at 17-22 GHz. The matrix incorporates passive circuits and switches, including biasing and decoupling networks, which enable digitally controlled reconfiguration. In a first attempt, we have designed a test chip to characterise different types of switches, and to identify the limits of the technology. The scattering
parameters measured for a 11-layer structure with 4 layers containing RF signal lines and minimum line widths of 40 mm prove the principle-of-operation. The results illustrate the potential of our approach and indicate routes to optimise the RF design.

Dept. of Microelectronics & Radio Engineering, St. Petersburg Electrotechnical University, 5 Prof. Popov st., 197376, St. Petersburg, Russia

Introduction
Microwave components for gain settings and control function have applications in a number of areas. Such the components are used in multichannel communication systems where the gains through different channels need equalization. Digitally controlled attenuators are also required for phased array antennas, 'smart' antennas and other similar applications. Design of a digital 5-bit GaAs MMIC attenuator with the operating frequency band of 8-12 GHz is presented in this paper. The attenuator consists of cascaded units of individual bit, which can be switched on or off to provide the desired value of attenuation from 0.75 dB to23.25 dB with the step of 0.75 dB.

Dept. of Microelectronics & Radio Engineering, St.-Petersburg Electrotechnical University, 5 Prof. Popov st., 197376, St. Petersburg, Russia.

Abstract – Design of front-end passive devices for Bluetooth and WLAN applications are presented. The devices of a small size have been realized using LTCC and multilayer "sandwich" technology and revealed a high performance.

Dept. of Microelectronics & Radio Engineering, St.-Petersburg Electrotechnical University, 5 Prof. Popov st., 197376, St. Petersburg, Russia.

Abstract – Possibilities of using multilayer "sandwich" technology for microwave applications are investigated. Various passive structures have been simulated, fabricated and measured. Simulated data are presented in a comparison with experimental results.

Dept. of Microelectronics & Radio Engineering, St. Petersburg Electrotechnical University, 5 Prof. Popov St., 197376, St. Petersburg, Russia

Abstract – The paper presents the three-pole microstrip bandpass filter without second spurious passband, which was suppressed by additional capacitors placed between resonators. The filter layout and simulation results are presented and discussed.