James M. Parisi

A 10 MHz to 100 GHz LTCC CPW-to-stripline vertical transition

A broadband 50Ω coplanar waveguide (CPW)-to-stripline transition is presented which is capable of operation up to 100 GHz. This vertical transition is fabricated in low-temperature co-fired ceramic (LTCC), and it is appropriate for system in package (SiP) module packaging. It was designed for wafer probing an LTCC module containing an embedded stripline. This compact transition occupies only two layers of nominal 5 mil thick tape. Both simulated and measured s parameter results are shown for back-to-back transitions up to 110 GHz. Measured insertion loss for a single transition is less than 0.3 dB near 60 GHz and less than 1 dB up to 100 GHz.

60 GHz patch antenna in LTCC with an integrated EBG structure for antenna pattern improvements

We present a 60 GHz LTCC aperture-coupled patch antenna with an integrated Sievenpiper EBG structure used for suppression of TM mode surface waves. This is believed to be the first demonstration of a Sievenpiper EBG structure used inside a millimeterwave LTCC antenna. The merit of this EBG structure is to yield a predicted 6 dB improvement in broadside directivity. Without the EBG structure, edge diffraction of surface waves degrades the pattern into two main beams. The combination of a new LTCC material system (DuPont 9K7 GreenTape™) along with laser ablation processing for fine line and fine slot definition allowed the integration of a successful EBG structure with an aperture coupled patch antenna.

60-GHz

This letter presents a 60-GHz 2 × 2 low temperature co-fired ceramic (LTCC) aperture-coupled patch antenna array with an integrated Sievenpiper electromagnetic band-gap (EBG) structure used to suppress TM-mode surface waves. The merit of this EBG structure is to yield a predicted 4-dB enhancement in broadside directivity and gain, and an 8-dB improvement in sidelobe level. The novelty of this antenna lies in the combination of a relatively new LTCC material system (DuPont Greentape 9K7) along with laser ablation processing for fine line and fine slot definition (50-μm gaps with +/ - 6 μm tolerance) allowing the first successful integration of a Sievenpiper EBG structure with a millimeter-wave LTCC patch array. A measured broadside gain/directivity of 11.5/14 dBi at 60 GHz is achieved with an aperture footprint of only 350 × 410 mil2 (1.78λ × 2.08λ) including the EBG structure. This thin (27 mil) LTCC array is well suited for chip-scale package applications.

2 \times 2

This paper presents characterization of low temperature co-fired ceramic (LTCC) based electromagnetic bandgap (EBG) structures, and a test method to measure the TM mode cutoff frequency at millimeter wave frequencies. This test method differs from prior art in that the TM mode surface wave launchers are fabricated in the same LTCC module as the EBG structure under test to realize a compact and repeatable test vehicle. A pair of two port transmission measurements will experimentally yield the TM mode cutoff frequency. This frequency defines the lower bound for the surface wave bandgap. The TM mode cutoff frequency is a very important parameter where EBG structures are integrated into millimeterwave LTCC antennas because this cutoff frequency must be lower than the antennas operational frequency range. This proposed test method may be used with any open EBG structure which exhibits a TM mode cutoff frequency.

LTCC Patch Antenna Array With an Integrated EBG Structure for Gain Enhancement

This paper presents characterization of low temperature co-fired ceramic (LTCC) based electromagnetic bandgap (EBG) structures. We show a new test method to measure the TE mode cutoff frequency of an EBG structure. This test method is implemented at millimeter wave frequencies. Exponentially-shaped TE mode surface wave launchers are fabricated in the same LTCC substrate as the EBG structure under test to realize a compact and repeatable test vehicle. A pair of two port coupling measurements experimentally yields the TE mode cutoff frequency, below which a bound TE mode surface wave is suppressed. The TE mode cutoff frequency is important where EBG structures are integrated into millimeterwave LTCC antennas because this cutoff frequency must be greater than the antennas operational frequency range. This proposed test method differs from previous experimental techniques because it employs a calibration test vehicle, and this test method provides a clear indication of the TE mode cutoff frequency.

Millimeter wave measurement of the TM mode cutoff for EBG structures fabricated in LTCC for antenna applications

Abstract Thick film material systems for hybrid applications have existed for many years and have provided the ability to create high density interconnects in industries such as consumer, military, telecommunications and automotive electronic devices. Despite their breadth of applications, thick film hybrid circuits are rarely utilized for microwave/millimeter-wave packaging applications. In this work, the DuPont™ QM44 thick film dielectric is characterized up to 40 GHz. Test samples to characterize this thick film system consisted of the screen-printed QM44 multilayer dielectric and QG150 gold thick film conductor and vias on top of a 96% alumina substrate. Three different fabrication methods were used in the fabrication of the test samples to illustrate the effect of processing techniques on material loss properties, with the conductor lines formed through standard screen printing, chemical etching, and laser ablation. Laser ablation is a technique recently utilized to form transmission line features in...

Measurement method for the TE mode cutoff frequency in EBG structures fabricated in LTCC for antenna applications

Presented here are the design, fabrication, and measurement results of a low temperature cofired ceramic (LTCC) chip-to-interposer transition utilizing a flip-chip ball grid array (BGA) interconnect that provides excellent electrical performance up to and including 80 GHz. A test board fabricated in LTCC is used as the interposer substrate and another smaller LTCC part is used as a surrogate chip for demonstration purposes. The BGA chip-to-interposer transition is designed as a back-to-back pair of transitions with an assembly consisting of an LTCC interposer, an LTCC test chip, and a BGA interconnect constructed with 260 μm diameter polymer core solder balls. The LTCC material employed is DuPont™ GreenTape™ 9K7. Full-wave simulation results predict excellent electrical performance from 10 MHz to 80 GHz, with the chip-to-interposer BGA transition having less than 0.5 dB insertion loss at 60 GHz and less than 1 dB insertion loss up to 80 GHz. In an assembled package (back-to-back BGA transitions), the inse...