Harufumi Mandai

Advanced multi-layer ceramic surface-mount functional components for telecommunications equipment

We have developed various kinds of miniatured chip-type ceramic monolithic electronic components such as chip LC filters, hybrid couplers and delay lines, using low temperature cofireable ceramics (LTCC) with copper inner electrodes. The outer electrodes are also made of copper plated by Ni and Sn. Based on such LTCC multilayering technologies, our advanced microwave circuit design technologies have recently developed a chip RF diode switch and such a switch with integrated low-pass filter in a small (6.7/spl times/5.0/spl times/3.0 mm in production, 5.4/spl times/4.0/spl times/2.8 mm under development), surface-mountable package. Those devices employ the monolithic ceramic substrate, which includes relevant passive elements in it, with copper inner electrodes and copper outer/surface electrodes plated by Ni and Au. This paper discusses related ceramic material systems, manufacturing process, circuit design technologies and operating parameters of those chip RF diode switches.

Passive integration with SAW filter using LTCC (low temperature co-fired ceramics) and multi-layer technology

Passive integration using LTCC (low temperature cofired ceramics) and multi-layer technology are going to be the key technology in the RF part of the cellular phones. They greatly contribute to the reduction of the size and weight of the handset, parts count, soldering points and RF design resources. The integration with antenna switch and SAW filters is the one of the biggest issue in GSM/DCS dual band and triple band phones. More integration is required in the next generation and some improvements are accordingly expected on SAW filters.

A low temperature cofired multilayer ceramic delay line with copper conductors

A distributed type chip delay line made of low-temperature fireable ceramics cofired with copper conductors has been developed. This product has very good stability at high frequency, metal shield layers built inside the chip, and features high reliability. This delay line is expected to be used for various high-frequency circuits, especially those requiring small devices: optical link interfaces, high-frequency measurement equipment, and supercomputers, for example.<<ETX>>