Modelling of double air-bridged structured inductor implemented by a GaAs integrated passive device manufacturing process

Abstract

In order to provide excellent performance and show the development of a complicated structure in a module and system, this paper presents a double air-bridge-structured symmetrical differential inductor based on integrated passive device technology. Corresponding to the proposed complicated structure, a new manufacturing process fabricated on a high-resistivity GaAs substrate is described in detail. Frequency-independent physical models are presented with lump elements and the results of skin effect-based measurements. Finally, some key features of the inductor are compared; good agreement between the measurements and modeled circuit fully verifies the validity of the proposed modeling approach. Meanwhile, we also present a comparison of different coil turns for inductor performance. The proposed work can provide a good solution for the design, fabrication, modeling, and practical application of radio-frequency modules and systems.

S- to X-Band Stretchable Inductors and Filters for Gigahertz Soft and Epidermal Electronics

“…The large variation in the Q -factor value (in comparison to the small variations of L and f res , see Figure j,k) is due to the RF probing contact resistance improvement under stretching (see Supporting Information Figure S8). In general, the high Q -factor values and the high f res values of the stretchable inductor, which are comparable to the reported microwave inductors fabricated on flexible , and rigid substrates, − are attributed to the high EM performance of the two compact spirals in the inductor . With the addition of the serpentine line, the overall Q -factor value and f res value degraded from that of the two spirals.…”

“…Together, the two spirals contribute about 70% (4.4 nH) of the total L value and the serpentine line contributes 1.6 nH. Figure g compares the Q -factors and f res of the stretchable inductor with other reports, showing the competency of the present work in comparison to the GHz stretchable inductor based on stretchable coils, to the previously demonstrated flexible inductor on PET , and conventional spiral inductors fabricated on rigid (Si: Q = 12; GaAs: Q = 22; GaN: Q = 10) substrates. With the high Q -factor and high f res , the stretchable inductor is expected to satisfy the need of wireless communication at various frequency bands, such as GSM (upper sideband of 1.9 GHz), Bluetooth (2.4 GHz), WLAN (2.4 GHz and 5.8 GHz), and emerging 5G applications (lower band of 3.5 GHz). , …”

“…Beyond 2 GHz, the L value increased with the degree of stretching, indicating the parasitic capacitance (C par ) of the stretchable inductor, which mainly came from the serpentine signal line, and decreased with stretching. The increased L 34 flexible, 47 and rigid (Si, 37 GaAs, 38 and GaN 39 ) RF inductors. value and the decreased C par value resulted in a decrease in the f res .…”

“…(f) Q -factors versus frequency for the two-spiral stretchable inductors under 20% elongation. (g) Benchmarking of the working frequency as a function of Q -factor for typical stretchable, flexible, and rigid (Si, GaAs, and GaN) RF inductors.…”

“…Spiral inductors, with variations of ring shapes (circle, square, hexagon, octagon, or other polygons), have been widely used in RFICs for a few decades now . They are featured with compact size, high resonance frequencies, scalable inductance values, and high Q factors, capable of fulfilling various functions like RF chokes, bias network, impedance matching, etc., and have been adopted in RFICs fabricated on Si, GaAs, and GaN substrates. The values of inductance ( L ) are determined by the number of coils and the mutual inductance between the coils.…”