Integrated Passive Device Technology Research Articles

Design of Hybrid Bandpass Filter Chips with High Selectivity and Wideband Using IPD and FBAR Technology

A novel hybrid bandpass filter (BPF) with wideband and high selectivity is proposed in this paper. The hybrid BPF is composed of two film bulk acoustic resonator (FBAR) cells and three lumped component resonators realized by the integrated passive device (IPD) technology. The ABCD matrix to S-parameters matrix method is used to calculate the frequency response of the BPF. Moreover, the expressions of transmission zeros (TZs) have been extracted. In the design process, an iterative design approach is proposed to improve the circuit and layout of the hybrid filter based on the packaged acoustic-electric hybrid simulation effect. Finally, two parts of the filter are packaged based on the flip-chip method, and two prototypes for the BPF are measured. The measured results of two chips with 3 dB fractional bandwidth of 13.7% and 15.8% are designed and fabricated, which verifies the validity of the proposed design principle.

Millimeter-wave wideband filtering on-chip antenna based on IPD technology

ABSTRACT A millimeter-wave wideband filtering on-chip antenna is proposed in this paper. Its operation frequency covers 32 GHz to 63 GHz, and the impedance fractional bandwidth reaches 63%. Based on the corner-fed patch antenna, the antenna in this work has a quasi-omnidirectional radiation pattern, and peak efficiency reaches 91.7%. By square slotting on the four sides of the patch and cross slotting on the center of the patch, the high-order mode is suppressed, which supports the wide operating frequency range with filtering characteristics. Split ring resonators are etched on the ground to strengthen filtering characteristics. Based on thin-film integrated passive device (IPD) technology, the proposed structure is applicable to the on-chip wideband and high-efficiency antenna array.

A miniaturized low-loss absorptive bandpass filter using IPD technology

In this article, a highly miniaturized absorptive bandpass filter based on a novel topology is presented. The filter topology utilizes a resistor-loaded network to achieve absorptive characteristics while additional capacitive coupling between series resonators is introduced to enhance selectivity. The proposed filter with a center frequency of 2.5 GHz and a 3-dB bandwidth of 2800 MHz is implemented using a GaAs integrated passive device (IPD) technology, exhibiting a small die size (0.7 mm×1.13 mm), low loss in-band insertion loss (0.9 dB), high out-of-band rejection (8.8f0¿25 dB), and a wide low-reflection frequency range. The measurement results show good agreement with the simulations. These features show promising applications in highly integrated RF systems.

A Multilayered GaAs IPD Resonator with Five Airbridges for Sensor System Application.

This work proposes a microwave resonator built from gallium arsenide using integrated passive device (IPD) technology. It consists of a three-layered interlaced spiral structure with airbridges and inner interdigital structures. For integrated systems, IPD technology demonstrated outstanding performance, robustness, and a tiny size at a low cost. The airbridges were made more compact, with overall dimensions of 1590 × 800 µm2 (0.038 × 0.019 λg2). The designed microwave resonator operated at 1.99 GHz with a return loss of 39 dB, an insertion loss of 0.07 dB, and a quality factor of 1.15. Additionally, an experiment was conducted on the properties of the airbridge and how they affected resistance, inductance, and S-parameters in the construction of the resonator. To investigate the impact of airbridges on the structure, E- and H-field distributions of the resonator were simulated. Furthermore, its use in sensing applications was explored. Various concentrations of glucose solutions were used in the experiment. The proposed device featured a minimum detectable concentration of 0.2 mg/mL; high sensitivity, namely, 14.58 MHz/mg·mL-1, with a linear response; and a short response time. Thus, this work proposes a structure that exhibits potential in integrated systems and real-time sensing systems with high sensitivity.

A Differential THz/MW Sensor for Characterizing Liquid Samples Based on CSRs

A differential on-chip sensor loaded with circular spiral resonators (CSRs) for charactering liquid samples is proposed in this manuscript. The proposed on-chip sensor is working at Terahertz (THz) frequency band, and the sensor can be fabricated by integrated passive device (IPD) technology. With comparison to square and octagonal spiral resonators, the circular spiral resonator (CSR) has a higher quality factor and a stronger confinement of electrical field, which are beneficial to improve the measurement sensitivity. The proposed sensor has a differential structure, and two circular spiral resonators are equally distributed on both sides of the microstrip line, and one resonator is regarded as reference, another is utilized as test. The frequency shift and notched magnitude of transmission coefficient will be changed by loading liquid samples with different complex permittivity, thus, the relevant mathematical relationship between S-parameters and permittivity can be established. However, as the cost of fabricating on-chip sensor by IPD technology is nearly half million of RMB, so printed circuit board (PCB) technology is used to fabricate the proposed sensor and to verify the feasibility of the sensor. It should be noted that the on-chip sensor operates at THz band, while the PCB-based sensor operates at MW band. The experiment shows that the proposed CSRs-based MW sensor has a high sensitivity of about 0.28 %. When the real permittivity changes by one unit, the resonant frequency shifts for the microwave sensor and THz sensor are about 0.445 GHz and 1.45 GHz, i.e., 0.445 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GHz</i> /εʹ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>r</i></sub> and 1.45 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GHz</i> /εʹ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>r</i></sub> , respectively. Obviously, the on-chip THz sensor has a higher resolution than the microwave sensor. All in all, the proposed differential microwave CSR-based sensor is a good candidate in the field of microfluidic measurement.

Design and Implementation of Broadband Hybrid 3-dB Couplers with Silicon-Based IPD Technology.

Heterogeneous integration (HI) is a rapidly developing field aimed at achieving high-density integration and miniaturization of devices for complex practical radio frequency (RF) applications. In this study, we present the design and implementation of two 3 dB directional couplers utilizing the broadside-coupling mechanism and silicon-based integrated passive device (IPD) technology. The type A coupler incorporates a defect ground structure (DGS) to enhance coupling, while type B employs wiggly-coupled lines to improve directivity. Measurement results demonstrate that type A achieves <-16.16 dB isolation and <-22.32 dB return loss with a relative bandwidth of 60.96% in the 6.5-12.2 GHz range, while type B achieves <-21.21 dB isolation and <-23.95 dB return loss in the first band at 7-13 GHz, <-22.17 dB isolation and <-19.67 dB return loss in the second band at 28-32.5 GHz, and <-12.79 dB isolation and <-17.02 dB return loss in the third band at 49.5-54.5 GHz. The proposed couplers are well suited for low cost, high performance system-on-package radio frequency front-end circuits in wireless communication systems.

Design of a Wideband Balun Using IPD Technology for Compensating the Frequency Dependency

In this paper, we propose a wideband balun using integrated passive device (IPD) technology. The proposed circuit is designed to compensate for the magnitude deviations by differentiating the magnitude S-parameter and calculating the lumped component value when the derivative value is zero. For a smaller size, the proposed circuit is implemented using IPD technology, and the fabricated circuit’s size is 2.4 mm × 1.02 mm. The magnitude of the measurement results has 3.5 ± 0.3 dB deviations from 2.8–4.58 GHz, and the phase difference has 180° ± 10° from 2.8–5 GHz at the center frequency of 3.6 GHz. Therefore, the measurement results show that the theory of the proposed circuit is well matched compared with the measurement results for smaller sizes, wideband magnitude, and phase characteristics.

A compact 5G band N77 bandpass filter with multiple zeros based on GaAs integrated passive device process

AbstractIn this paper, a compact 5G band N77 bandpass filter (BPF) with multiple zeros is designed based on GaAs integrated passive device (IPD) process. The BPF consists of lumped capacitors and inductors. Hybrid resonator technology which consists of a combination of shunt and series resonant tanks are proposed to produce six transmission zeros in the stopband and significantly improve the filter selectivity. In addition, a series resonator at the output port of the filter was introduced to produce another transmission zero at the upper stopband and further improve the stopband suppression. Meanwhile, to reduce the area and insertion loss of the filter, a stacked inductor is designed by using IPD technology, which can greatly reduce the area and size of the filter. The minimum insertion loss is 1.782 dB. The size of the entire BPF is 1.3 mm × 0.7 mm.

Wideband High Selectivity Filter Chips With Adjustable Bandwidth Based on IPD Technology

In this brief, two kinds of wideband high selectivity passband filter chips with adjustable bandwidth are proposed. Independent controllable transmission zeros are introduced on both sides of the passband by LC resonators. Two designs are analyzed and calculated by means of odd-even mode analytical method and ABCD matrix to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${S}$ </tex-math></inline-formula> -parameters matrix method. Finally, integrated passive device (IPD) technology was used to process two versions of broadband and narrowband filters for each design, with a total number of four filter chips. The measured results show that 3-dB fractional bandwidth (FBW) of the first design are 19.3% and 83.6% respectively, which have verified a large degree of freedom in bandwidth control. In addition, the return loss of four chips is better than 17 dB, the optimal insertion loss ranges from 1.31 dB to 2.73 dB, and the stopband rejection is better than 25.2 dB, indicating excellent overall performance.

A Cost-Effective W-Band Antenna-in-Package Using IPD and PCB Technologies

This paper presents a cost-effective millimeter-wave (W-band) cavity-backed slot antenna-in-package (AiP) built by using commercially available integrated passive device (IPD), printed circuit board (PCB), and flip-chip assembly technologies. An IPD-PCB resonant cavity is formed by flipping an IPD chip on a PCB substrate with surrounding solder bumps to provide radiation through a square slot, which is patterned on one of the IPD metal layers. Moreover, a substrate integrated waveguide (SIW) cavity under the IPD-PCB cavity and a wideband grounded coplanar waveguide (GCPW) are built in the PCB substrate for the transition between a radio-frequency front-end (RFFE) and the IPD-PCB cavity. The fabricated AiP achieves a 3.75-dBi gain at 94.5 GHz (TE210 mode) and a 10-dB impedance bandwidth of 1.9 GHz with a 3.61 mm2 IPD chip area.

Compact wideband Wilkinson power divider on gallium arsenide integrated passive device technology

In this article, a novel topology of wideband on-chip Wilkinson power divider (WPD) with good insertion loss (IL) performance is proposed and demonstrated on gallium arsenide (GaAs)-based integrated passive device (IPD) technology. The proposed WPD is further analyzed by the even and odd method. To verify the advantage of the proposed WPD against the conventional one, two examples are numerically investigated, showing that the proposed one achieves better performance in terms of IL and isolation. In addition, the proposed design achieves a miniature area and small amplitude and phase imbalance (AI) performance. The fractional bandwidth (FBW) of the proposed WPD is 100% (6–18 GHz), where the magnitude imbalance is less than 0.08 dB and phase imbalance is better than 0.4°. Furthermore, the minimum IL is better than 0.96 dB and return loss is better than 13.7 dB within the core passband. Meanwhile, the isolation of the WPD is better than 17.6 dB. Finally, to further demonstrate our design conception, the proposed WPD has been fabricated on GaAs IPD technology with size of 1.5 × 0.9 mm2, and measured by on-wafer probing. All the simulated and measured results of the proposed WPD are matched reasonably well with each other, thus firmly validating the claimed superior performance of the proposed WPD in the wide operating bandwidth, low IL and high isolation.

Compact and High-Order On-Chip Wideband Bandpass Filters on Multimode Resonator in Integrated Passive Device Technology

Compact and High-Order On-Chip Wideband Bandpass Filters on Multimode Resonator in Integrated Passive Device Technology

Bandpass Filter With Ultra-Wide Upper Stopband on GaAs IPD Technology

In this brief, a novel bandpass filter (BPF) with ultra-wide upper stopband performance is proposed and implemented on gallium arsenide (GaAs) integrated passive device (IPD) technology. Firstly, the proposed BPF is designed by introducing a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\boldsymbol{\pi }$ </tex-math></inline-formula> -section to achieve an ultra-wide upper stopband. Following that, the working principle of achieving this ultra-wideband upper stopband performance is further investigated. Finally, to demonstrate the claimed performances, this BPF with a size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.63 {\mathrm {\times }}0.62$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> has been fabricated on GaAs IPD technology and measured by on-wafer probing. The measured BPF with a 3-dB fractional bandwidth (FBW) of 95.3% (1.7-4.8 GHz), exhibits the expected performances, especially the superior upper stopband suppression level better than 20 dB until 110 GHz (34.6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f} _{0}$ </tex-math></inline-formula> ). The simulated and measured results of the BPF are in reasonably good agreement, thus firmly validating the claimed superior performances of the BPF in terms of good frequency selectivity and ultra-wide upper stopband.

Design and Micro-Nano Fabrication of a GaAs-Based On-Chip Miniaturized Bandpass Filter with Intertwined Inductors and Circinate Capacitor Using Integrated Passive Device Technology.

In this study, we propose a miniaturized bandpass filter (BPF) developed by combining an approximate circular (36-gon) winding inductor, a circinate capacitor, and five air-bridge structures fabricated on a gallium arsenide (GaAs) substrate using an integrated passive device (IPD) technology. We introduced air-bridge structures into the outer metal wire to improve the capacitance per unit volume while utilizing a miniaturized chip with dimensions 1538 μm × 800 μm (0.029 λ0 × 0.015 λ0) for the BPF. The pattern was designed and optimized by simulating different dimensional parameters, and the group delay and current density are presented. The equivalent circuit was modeled to analysis various parasitic effect. Additionally, we described the GaAs-based micro-nano scale fabrication process to elucidate the proposed IPD technology and the physical structure of the BPF. Measurements were conducted with a center frequency of 1.53 GHz (insertion loss of 0.53 dB) and a 3-dB fractional bandwidth (FBW) of 70.59%. The transmission zero was located at 4.16 GHz with restraint of 35.86 dB. Owing to the benefits from its miniaturized chip size and high performance, the proposed GaAs-based IPD BPF was verified as an excellent device for various S-band applications, such as satellite communication, keyless vehicle locks, wireless headphones, and radar.

Compact wideband Wilkinson power divider on GaAs integrated passive device technology

In this article, a novel topology of wideband on-chip Wilkinson power divider (WPD) with good insertion loss (IL) performance is proposed and demonstrated on gallium arsenide (GaAs)-based integrated passive device (IPD) technology. The proposed WPD is further analyzed by the even and odd method. To verify the advantage of the proposed WPD against the conventional one, two examples are numerically investigated, showing that the proposed one achieves better performance in terms of IL and isolation. In addition, the proposed design achieves a miniature area and small amplitude and phase imbalance (AI) performance. The fractional bandwidth (FBW) of the proposed WPD is 100% (6-18 GHz), where the magnitude imbalance is less than 0.08 dB and phase imbalance is better than 0.4°. Furthermore, the minimum IL is better than 0.96 dB and return loss is better than 13.7 dB within the core passband. Meanwhile, the isolation of the WPD is better than 17.6 dB. Finally, to further demonstrate our design conception, the proposed WPD has been fabricated on GaAs IPD technology with size of 1.5 × 0.9 mm2, and measured by on-wafer probing. All the simulated and measured results of the proposed WPD are matched reasonably well with each other, thus firmly validating the claimed superior performance of the proposed WPD in the wide operating bandwidth, low IL, and high isolation.

Compact wideband Wilkinson power divider on gallium arsenide‐based integrated passive device technology

In this article, a novel topology of wideband on-chip Wilkinson power divider (WPD) with good insertion loss (IL) performance is proposed and demonstrated on gallium arsenide (GaAs)-based integrated passive device (IPD) technology. The proposed WPD is further analyzed by the even and odd method. To verify the advantage of the proposed WPD against the conventional one, two examples are numerically investigated, showing that the proposed one achieves better performance in terms of IL and isolation. In addition, the proposed design achieves a miniature area and small amplitude and phase imbalance (AI) performance. The fractional bandwidth (FBW) of the proposed WPD is 100% (6-18 GHz), where the magnitude imbalance is less than 0.08 dB and phase imbalance is better than 0.4°. Furthermore, the minimum IL is better than 0.96 dB and return loss is better than 13.7 dB within the core passband. Meanwhile, the isolation of the WPD is better than 17.6 dB. Finally, to further demonstrate our design conception, the proposed WPD has been fabricated on GaAs IPD technology with size of 1.5 × 0.9 mm2, and measured by on-wafer probing. All the simulated and measured results of the proposed WPD are matched reasonably well with each other, thus firmly validating the claimed superior performance of the proposed WPD in the wide operating bandwidth, low IL, and high isolation.

Low-Loss Low-Cost Substrate-Integrated Waveguide and Filter in GaAs IPD Technology for Terahertz Applications

A low-loss and low-cost terahertz (THz) substrate-integrated waveguide (SIW) and a SIW filter implemented in a commercially-available GaAs integrated-passive-devices (IPD) technology are proposed for THz applications. Ellipse vias penetrating through a 100- $\mu \text{m}$ thick GaAs substrate are employed to realize a low-loss SIW. The via’s orientation is designed as being transverse, instead of being longitudinal, to the propagation direction of the input wave, which can improve the insertion loss by 2.7 dB at 415 GHz due to lower signal leakage from the waveguide. The proposed SIW is able to provide simulated insertion loss of only 0.39 dB/mm, i.e., 0.14 dB/ $\lambda _{\mathrm {g}}$ , at 340 GHz. A new SIW filter structure using the ellipse vias is proposed which not only successfully realizes a low-loss fourth-order Chebyshev filter under hard design-rule-check (DRC) rules imposed by the IPD technology, but also can enhance out-of-band rejection by 10.5 dB at 390 GHz as compared with conventional waveguide filters. A slot-coupled coplanar waveguide (CPW) to SIW transition structure without any impedance tuning stub required is also proposed to measure the proposed SIW and SIW filter. The proposed transition structure can give simulated insertion loss of 0.7 dB at 340 GHz while keeping return loss better than 10 dB from 307 to 374 GHz. Eight samples are measured to demonstrate the robustness of the proposed designs against process variations. Experimental results show that the proposed transition structure with a 220- $\mu \text{m}$ long SIW and the SIW filter can provide measured insertion loss of 0.7 and 3.6 dB at 327.5 GHz, respectively. The reasons for the discrepancy between the simulation and measurement results are identified and discussed in detail. As compared with prior works, the proposed SIW and SIW filter exhibit lower loss, lower cost, higher repeatability, higher reliability, and mass-producible capability. To the best of the authors’ knowledge, this is the first demonstration of the THz SIW and THz SIW filter designs using a commercially-available and mass-producible IPD technology reported thus far.

An Ultraminiaturized Bandpass Filtering Marchand Balun Chip With Spiral Coupled Lines Based on GaAs Integrated Passive Device Technology

The integrated passive device (IPD) technology has become a new research hotspot, and it depends on electrical characteristics of GaAs, NiCr, and Si3N4 to construct radio frequency (RF) components. RF elements constructed by the IPD technology have features of high quality and ultra-small size, especially for capacitors and inductors. In order to realize the miniaturization of RF circuits, dimensions become as small as possible. Consequently, the layout of a spiral coupled line (SCL) cannot be drawn freely, so that it has uncontrollable odd- and even-mode impedances and a large coupling coefficient, which may limit the design of the traditional Marchand balun negatively. This article solves this problem by designing a GaAs IPD Marchand balun with 1/8-wavelength coupled lines (CLs) and using a capacitor termination to replace the open end in the conventional Marchand balun. Meanwhile, a filter is added to realize a filtering function. The proposed bandpass filtering Marchand balun (BFMB) chip has a size of 1.49 mm $\times1.39$ mm, and measured results indicate that it has an operation band of 2.39–5.68 GHz with a phase imbalance of 5.26° and a magnitude imbalance of less than 0.35 dB.

Ultraminiaturized Wideband Quasi-Chebyshev/-Elliptic Impedance-Transforming Power Divider Based on Integrated Passive Device Technology

This article presents the ultraminiaturized wideband quasi-Chebyshev and -elliptic low-pass power dividers (PDs) with an impedance-transforming function using integrated passive device (IPD) technology, occupying only the sizes of $1.1\times1.2$ mm2 and $1.1\times1.6$ mm2, respectively. The generalized quasi-Chebyshev low-pass matching network with the detailed design procedure is utilized to construct the circuit schematic of the proposed wideband PD. In order to further improve stopband rejection, a quasi-elliptic network is introduced, resulting in an extra transmission zero (TZ). For demonstration, the quasi-Chebyshev and -elliptic PDs based on IPD technology are designed, manufactured, and measured, respectively. Measurements indicate that the quasi-elliptic PD with TZ shows good electrical responses, including lower than 1.08-dB insertion loss, all better than 15-dB return loss and isolation from 2.49 to 5.0 GHz.

On-Chip Miniaturized Bandpass Filter Using GaAs-Based Integrated Passive Device Technology For L-Band Application.

In this work, a miniaturized bandpass filter (BPF) constructed of two spiral intertwined inductors and a central capacitor, with several interdigital structures, was designed and fabricated using integrated passive device (IPD) technology on a GaAs wafer. Five air-bridge structures were introduced to enhance the mutual inductive effect and form the differential geometry of the outer inductors. In addition, the design of the differential inductor combined with the centrally embedded capacitor results in a compact construction with the overall size of 0.037λ0 × 0.019λ0 (1537.7 × 800 μm2) where λ0 is the wavelength of the central frequency. For the accuracy evolution of the equivalent circuit, the frequency-dependent lumped elements of the proposed BPF was analyzed and modeled through the segment method, mutual inductance approach, and simulated scattering parameters (S-parameters). Afterward, the BPF was fabricated using GaAs-based IPD technology and a 16-step manufacture flow was accounted for in detail. Finally, the fabricated BPF was wire-bonded with Au wires and packaged onto a printed circuit board for radio-frequency performance measurements. The measured results indicate that the implemented BPF possesses a center frequency operating at 2 GHz with the insertion losses of 0.38 dB and the return losses of 40 dB, respectively, and an ultrawide passband was achieved with a 3-dB fraction bandwidth of 72.53%, as well. In addition, a transmission zero is located at 5.32 GHz. Moreover, the variation of the resonant frequency with different inductor turns and metal thicknesses was analyzed through the simulation results, demonstrating good controllability of the proposed BPF.