Quasi-Elliptic and Chebyshev Compact LTCC Multi-Pole Filters Functioning in the Submillimetric Wave Region at 150 GHz

Abstract

This paper proposes, for the first time to the best of our knowledge, two challenging LTCC multi-pole bandpass filters operating at 150 GHz for radioastronomy applications. Low-temperature co-fired ceramic (LTCC) technology is employed to realize these filters because it assures the high precision and compactness needed at this high frequency. The two filters are optimized by 3-D electromagnetic simulations and are validated by experimental results. Different positive and negative couplings, which are achieved by different coupling apertures, are studied. The five-pole Chebyshev filter has 8.4 dB of insertion loss in a 1.31% fractional bandwidth for 6.7 mm 2.45 mm lateral dimensions. The fourpole quasi-elliptic filter is conceived to decrease insertion loss by decreasing the number of resonant cavities while conserving the same selectivity by introducing two transmission zeros around the passband. Beside 5.5 dB of insertion loss, this filter occupies a more compact circuit area (3.32 mm 2.37 mm) and insures a very good spurious free region (16 GHz) around 150 GHz. Experimental results are in good agreement with the theoretical ones and validate the use of LTCC technology at such high frequencies over 100 GHz.

CMOS 170 GHz combline bandpass filter

“…The return loss is below -15 dB in the pass band. Compare with the BPFs fabricated in low temperature co-fired ceramic (LTCC) [13] and micromachined technology [14], the proposed combline BPF is more compact and ease of integrated.…”

Substrate Integrated Waveguide Bandpass Filters implemented on Silicon Interposer for Terahertz Applications

“…In addition, it overcomes the limitations associated with transmission line dimensions due to short wavelengths, and therefore the frequency limitation of integrated passive devices (IPD). The use of SIW technologies have already been proposed in G-band using LTCC technologies [18]- [19] or air-filled SIW on silicon [20]- [21]. However, the use of low dielectric constant led to bulky filters which are not compatible with system integration.…”

RF Components Based on Advanced Additive Technologies

“…In terms of integration, main requirements are to be able to manufacture complex 2D and 3D miniature structures and to mix dielectric materials and metals. LTCC (Low temperature co-fired ceramic) [1] is a possible approach. It allows the use of low temperature fired ceramic material and high conductivity metals (gold, silver).…”