17.Miniaturization Technology

Advances in integrated IC technologies have been applied to various LSI, HIC, MIC and MMIC elements, thereby substantially contributing to miniaturization and reducing the number of components.

Mobile communications LSIs can be classified into four types in terms of the manufacturing process: GaAs, bipolar, Bi-CMOS and CMOS. From the standpoint of operating frequencies, they can also be classified into the high-frequency band between 1 to 3 GHz, the intermediate frequency band between 10 to 200 MHz and the base band of 40 MHz or less. As there are upper limits to the operating frequency of each process, it is necessary to select and apply a specific process to suit the applicable circuit.

An MMIC is a high-frequency band IC that integrates active devices such as transistors and passive circuits such as resistors, capacitors and inductors on semiconductor substrates made of gallium arsenic or silicon. Using MMICs offers a number of advantages as they can be significantly more compact and lighter weight than hybrid ICs, etc., are easy to mass produce, offer excellent reproductivity, and permit high integration. Progress has been made in shifting RF-band and IF-band circuits to MMIC in the structuring of mobile units, and efforts are being made to adopt card technology for MMICs.

LSI Categories for Mobile Communications

Created 1999/03