Advantages Of Tunable RF MMIC Filter Technology

Marki Microwave’s MFBT series of tunable MMIC filters addresses traditional challenges in tunable bandpass filtering by providing a flexible, compact, and high-performance solution. Designed to streamline RF system complexity and size, MFBT filters offer a wide tuning range, excellent in-band and out-of-band return loss, and simplified control. Unlike switched filter banks, which use fixed filters and multiple switches, the MFBT filter architecture consists of tunable highpass and lowpass stages that enable continuous tuning across frequency bands. This architecture eliminates the need for multiple control lines, using only two control voltages (0–16V) to adjust filter corners.

The MFBT filters are significantly smaller than switched filter banks, occupying a 4x4mm package, making them ideal for applications prioritizing compactness and ease of use. Although switched filter banks provide superior out-of-band rejection and passband flatness, their complexity, larger size, and limited tuning flexibility make them less versatile than MFBT filters. The MFBT series can achieve constant or variable bandwidth, making it highly adaptable for applications where precise tuning is essential.

A demonstration platform showcased the MFBT filter’s performance compared to a 4-state switched filter bank, allowing users to observe tuning flexibility and ease of control. With models covering frequencies from 3 to 30 GHz, the MFBT series provides a versatile option for applications requiring a balance of tuning range, compact size, and reliable signal integrity, making it a robust alternative to traditional filter banks.