Integrated Passive Device Research Articles

IPD-Based Miniaturized Wideband Bandpass Filter With Frequency-Dependent Complex Source and Load

In this article, an ultraminiaturized bandpass-filtering matching network based on GaAs substrate integrated passive device (IPD) technology is proposed, which is suitable for frequency-dependent complex source and load. The presented bandpass filter (BPF) is derived from an equal-ripple Chebyshev low-pass filter prototype through frequency transformation and impedance scaling. The susceptance required by the source and load is extracted from the adjacent susceptance blocks, and the final reactance/susceptance block is equivalent to a series/parallel LC circuit at the two edge frequencies. Therefore, the proposed design has both bandpass high-selectivity and impedance matching functions, and simultaneously, the bandwidth can be flexibly controlled. Finally, a wideband BPF example with the center frequency of 3.5 GHz was simulated and fabricated with the IPD process, showing satisfactory performances.

340-GHz Heterogeneously-Integrated THz Imager With 4°-Beamwidth 16×16 IPD Antenna Array for Lensless Terahertz Imaging Applications

A low-cost and planar heterogeneously-integrated 340-GHz THz imager is proposed for lensless THz imaging applications. The proposed THz imager is composed of a 16×16 antenna array realized in an integrated-passive-device (IPD) technology, an IPD-to-CMOS THz interconnect, and a power detector implemented in a 0.18- μm CMOS technology. The 16×16 IPD antenna array can provide simulated antenna gain of 23.9 dBi, antenna directivity of 30 dB, and half-power beamwidth (HPBW) of 5.6° at 340 GHz. The proposed THz interconnect utilizes a transmission line coupling technique to provide low-loss and broadband signal transition from a CMOS chip to an IPD one while occupying a small chip area. The simulated insertion loss of the THz interconnect is only 1.8 dB at 340 GHz while providing 3-dB bandwidth from 230 to 446 GHz. The power detector exploits the transistor's inherent even-order nonlinearity to rectify the input signal for power detection. The power detector can give simulated voltage responsivity R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</sub> and noise equivalent power (NEP) of 190.2 kV/W and 1.9 nW/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sup> at 340 GHz, respectively, as the chopping frequency f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mod</sub> is 1 kHz. A nonlinear curve fit technique is proposed to tackle the undesired fluctuation of the measured output voltage due to a standing-wave effect. Experimental results show that the proposed heterogeneously-integrated THz imager can provide measured effective R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</sub> and NEP of 0.967 MV/W and 0.18 nW/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sup> at 328 GHz, respectively, as f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mod</sub> is 1 kHz. The measured antenna directivity and HPBW can be 30 dB and 4° at 340 GHz, respectively. Such a THz imager with advantages of high antenna directivity and narrow HPBW can be employed to realize a simple, low-cost, and lensless THz imaging system. To the best of the authors' knowledge, the proposed THz imager integrates the highest number of antennas and exhibits the highest antenna directivity and the narrowest HPBW at THz frequencies reported thus far.

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.

Determination of Characteristic Impedance of Planar Transmission Lines on Lossy/Dispersive Substrates by Using Series Resistor With Frequency-Dependent Inductance

This article presents a simple derivation and fast-solving scheme to extract the characteristic impedance of planar transmission lines (TLs) on lossy/dispersive substrates, by using a series resistor after one-tier multiline thru-reflect-line (TRL) calibration, for on-wafer calibration applications. The proposed method is based on the constant resistance condition of the series resistor and linear frequency response of the conductance of TL per unit length, where the parasitic inductance of the series resistor can be frequency-dependent; thus, the deviation caused by the constant inductance assumption can be observed in millimeter-wave frequencies. The proposed method is investigated using a coplanar waveguide (CPW) on a high-resistivity silicon substrate by using an integrated passive device (IPD) technology with verifications of the calibration comparison method in a frequency range of 2–110 GHz.

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.

Fabrication of QFN-Packaged Miniaturized GaAs-Based Bandpass Filter with Intertwined Inductors and Dendritic Capacitor.

This article presents a compact quad flat no-lead (QFN)-packaged second-order bandpass filter (BPF) with intertwined inductors, a dendritic capacitor, and four air-bridge structures, which was fabricated on a gallium arsenide (GaAs) substrate by integrated passive device (IPD) technology. Air-bridge structures were introduced into an approximate octagonal outer metal track to provide a miniaturized chip size of 0.021 × 0.021 λ0 (0.8 × 0.8 mm2) for the BPF. The QFN-packaged GaAs-based bandpass filter was used to protect the device from moisture and achieve good thermal and electrical performances. An equivalent circuit was modeled to analyze the BPF. A description of the manufacturing process is presented to elucidate the physical structure of the IPD-based BPF. Measurements were performed on the proposed single band BPF using a center frequency of 2.21 GHz (return loss of 26.45 dB) and a 3-dB fractional bandwidth (FBW) of 71.94% (insertion loss of 0.38 dB). The transmission zero is located at the 6.38 GHz with a restraint of 30.55 dB. The manufactured IPD-based BPF can play an excellent role in various S-band applications, such as a repeater, satellite communication, and radar, owing to its miniaturized chip size and high performance.

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.

Reusable, Non-Invasive, and Ultrafast Radio Frequency Biosensor Based on Optimized Integrated Passive Device Fabrication Process for Quantitative Detection of Glucose Levels.

The increase in the number of people suffering diabetes has been the driving force behind the development of glucose sensors to overcome the current testing shortcomings. In this work, a reusable, non-invasive and ultrafast radio frequency biosensor based on optimized integrated passive device fabrication process for quantitative detection of glucose level was developed. With the aid of the novel biosensor design with hammer-shaped capacitors for carrying out detection, both the resonance frequency and magnitude of reflection coefficient can be applied to map the different glucose levels. Meanwhile, the corresponding fabrication process was developed, providing an approach for achieving quantitative detection and a structure without metal-insulator-metal type capacitor that realizes low cost and high reliability. To enhance the sensitivity of biosensor, a 3-min dry etching treatment based on chlorine/argon-based plasma was implemented for realizing hydrophilicity of capacitor surface to ensure that the biosensor can be touched rapidly with glucose. Based on above implementation, a non-invasive biosensor having an ultrafast response time of superior to 0.85 s, ultralow LOD of 8.01 mg/dL and excellent reusability verified through five sets of measurements are realized. The proposed approaches are not limited the development of a stable and accurate platform for the detection of glucose levels but also presents a scheme toward the detection of glucose levels in human serum.

Compact and low insertion loss UWB on‐chip bandpass filter using coupled meandered line

AbstractFor ultra‐wideband (UWB) communication applications, a low‐loss compact filter is proposed based on coupled lines using the GaAs integrated passive devices (IPD) technology in this letter. The multistage coupling lines are used to realize the ultra‐wide passband with 100% fractional bandwidth. Two modified stubs loaded with shorted capacitors are introduced between coupled lines to produce a new transmission zero near the lower passband edge, resulting in better frequency selectivity performance. Moreover, stepped impedance resonator (SIR) structure is applied to the coupled lines to improve impedance matching performance within ultra‐wide passband. As demonstrated, the proposed filter is fabricated as a chip with a compact size of 1.8 × 1.7 mm2, that is, 0.257 × 0.242 λg2. The measured results show that the insertion loss of the filter is less than 1.5 dB from 6 to 18 GHz with the return loss better than 13.5 dB. All simulated and measured frequency responses of the proposed filter are found to match well with each other, which further demonstrates the claimed superior performances of the proposed filter.

A broadband RLC matched GaN power amplifier using interposer‐MMIC technology

AbstractIn this article, we report a compact and low‐profile GaN‐based broadband power amplifier using silicon interposer‐MMIC (iMMIC) technology. The iMMIC technology enables a GaN HEMT to be embedded in the silicon substrate, and passive circuit elements such as metal‐insulator‐metal (MIM) capacitors, spiral inductors, and thin film resistors to be implemented on the high‐resistivity silicon (HRS) substrate using standard integrated passive device (IPD) process, so that the final power amplifier is almost indistinguishable from a single GaN MMIC power amplifier. The RLC matched all‐pass network and LC ladder type low‐pass network are employed as the input matching network and output matching network, respectively. The proposed power amplifier has a Psat of 39.1 to 39.2 dBm with a power‐added efficiency (PAE) of 40% to 50.5% in the frequency range of 2.1 to 3.5 GHz under continuous wave (CW) input signal. The proposed iMMIC power amplifier occupies only 9.9 mm2.

1.34‐to‐16.37 GHz on‐chip balun based on asymmetric stacked spiral transformers

A novel broadband balun of owning bandwidth of more than a decade octaves is proposed, which is comprised of two parallel stacked spiral transformers with slightly different dimensions. The equivalent coupled line model reveals that the amplitude imbalance of the balun with symmetric structure equals to the coupling coefficient of the coupled line in decibel. Therefore, with higher coupling degree comes smaller amplitude imbalance. Furthermore, combined with the high coupling degree of stacked spiral transformers, the balun of owning optimal amplitude balance can be realised by slightly adjusting the size of one side transformer. Finally, the balun is designed and fabricated in Sanan's integrated passive device (IPD) process and its core size occupies an area of 690 μ m × 240 μ m . The simulation and measurement agree well in general, exhibiting a bandwidth covering from 1.34 up to 16.37 GHz with good return loss, flat insertion loss and high stability of 180° phase difference.

On-Chip Dual-Band Millimeter-Wave Power Divider Using GaAs-Based IPD Process

A new on-chip dual-band Wilkinson power divider (WPD), developed on a GaAs-based integrated passive device (IPD) process, is designed at 28/60 GHz for millimeter-wave (mmW) applications. Composite right/left-handed lines in microstrip form are employed to achieve the dual-band property. Thanks to the low-loss feature of the GaAs-based IPD process, the proposed mmW WPD ensures comparable performance when compared to its counterparts at microwave frequencies. Besides, the proposed design, one of the few on-chip dual-band WPDs designed in mmW bands, yields better performance in terms of input matching and power loss when compared with the previous work.

Millimeter-Wave Antenna-in-Package Applications Based on D263T Glass Substrate

SCHOTT D263T glass substrate is investigated for millimeter-wave (mm-wave) antenna-in-package applications using integrated passive device (IPD) technology. For comparison, the ring-resonator method and transmission-line method are used to extract the dielectric constant ($\varepsilon \text{r}$ ) of the glass substrate up to 67 GHz. The extracted results show good correlation between the two methods. Compared with the ring-resonator method, the transmission-line method requires higher measurement and simulation accuracies as the frequency decreases. Based on the extracted substrate data, a miniaturized Yagi-Uda dipole antenna operating at 60 GHz is designed, fabricated and measured. The measured results show that the antenna achieves a fractional impedance bandwidth (|S11| <; -10$ dB) of 57.1% (i.e. 36.4 to 65.5 GHz), and stable gains of 5.5± 0.5 dBi from 40 to 67 GHz with the dimension of 3.4 × 4 mm 2 . The simulated radiation efficiency is >90% from 45 to 67 GHz, and the measured results agree well with the simulations.

A High-Performance Common-Mode Noise Absorption Circuit Based on Phase Modification Technique

In this article, a high-performance common-mode noise absorption circuit (CMNAC) is proposed for solving electromagnetic interference (EMI) or radio-frequency interference (RFI) problems in high-speed differential digital systems. Instead of reflecting common-mode noises by conventional common-mode filters (CMFs), the common-mode noises can be absorbed in the proposed circuit. In addition, the phase modification technique is utilized to enhance the common-mode noise absorption rate and the differential-mode eye diagram in this CMNAC. In the common-mode half circuit (CMHC), the phase inversion of the subnetwork adds a destructive combination of the stopband energy, resulting in higher stopband attenuation. In the differential-mode half circuit (DMHC), the phase linearization leads to flat group delay, reducing the distortion in high-speed digital signal transmission in the lumped circuit. Using a standard integrated passive device (IPD) process, this CMNAC is implemented for the demonstration. The circuit occupies an area of only 1.138 mm $\times0.822$ mm. From the measured results, the proposed circuit exhibits the common-mode suppression level larger than 15 dB from 4 to 20 GHz and the absorption rate over 90% from 3.8 to 17.4 GHz with a fractional bandwidth 128%. In addition, the measured eye diagram shows that the proposed circuit can support high-speed transmission up to 10 Gb/s.

Compact and low-loss diplexer design and fabrication for WLAN/WiMAX application

ABSTRACTIn this paper, a compact and low-loss diplexer is designed and fabricated using integrated passive device (IPD) technique. This IPD-based diplexer can be utilized in antenna system for WLAN and WiMAX applications. It is composed of a low-pass filter and a high-pass filter, built on the GaAs substrate with the overall size of 0.95 × 0.95 mm2. The IPD diplexer realizes a dual-mode operation of 2.4 GHz for WLAN and 3.3 GHz to 3.8 GHz for WiMAX, respectively. The measurement results match well with the simulation results, in which the insertion loss at operation bands are below 0.5 dB (2.4 GHz) and 0.64 dB (3.3 GHz to 3.8 GHz), and the stopband suppression keeps higher than 20 dB.

Compact mm-Wave Bandpass Filters Using Silicon Integrated Passive Device Technology

In this letter, a compact bandpass filter (BPF) using integrated passive device (IPD) technology is presented, which is based on a pair of coupled-line inductors. To analyze the principle of this design, a simple but effective equivalent circuit model is provided. Using this model, it is easy to increase the number of resonators order. This structure is implemented by using a Si-based IPD process in which line inductors are located on a thick laminated organic ( $H = 40\,\,\mu \text{m}$ ) with a ground metal for shielding of lossy silicon. The minimum insertion loss of two-resonator BPF is 1.1 dB, and cascaded two-resonator structure is 2.3 dB. The size of two-resonator and cascaded two-resonator BPFs, excluding the pads, are only 0.246 $\text {mm} \times 0.44$ mm and 0.492 $\text {mm} \times 0.88$ mm, respectively.

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.

High performance miniaturized compact diplexer based on optimized integrated passive device fabrication technology

In this study, we proposed a compact miniaturized diplexer using 650 μm polished gallium arsenide (GaAs) substrate via thin film integrated passive device (TF-IPD) fabrication technology. The introduction of the three-order elliptic function diplexer can achieve low insertion loss and high isolation between the two outputs with a dimension of 1.9 mm × 0.8 mm × 0.2 mm (0.0053 λ0 × 0.0023 λ0 × 0.0005 λ0). The optimized IPD techniques for spiral inductor and metal-insulator-metal capacitor (MIMCAP) are discussed to achieve high Q-factor and excellent stability of the fabricated devices. Notably, the compact GaAs-based diplexer exhibits high performance with insertion loss of 0.5 dB and return loss larger than 16 dB. Besides, the isolation level between the two output ports is higher than 30 dB, which ensures the two ports can work independently without interference from each other. This study provides a facile fabrication approach for global system for mobile communications (GSM) and wideband code division multiple access (WCDMA) wireless communication systems.

Analytical Noise Optimization of Single-/Dual-Band MOS LNAs With Substrate and Metal Loss Effects of Inductors

Analytical noise formulations and design optimization of single- and dual-band inductively source-degenerated MOS low-noise amplifiers (LNAs) with the substrate and metal loss effects of on-chip inductors are established in this paper. It reveals that the noise figures of both single-/dual-band LNAs degrade substantially under the consideration of the loss effects. However, by increasing the device size, the noise optimization methodology of simultaneous noise and input match for a single-band LNA still holds true with concern for the loss effects. For a dual-band LNA, analytical noise optimization for a balanced noise design is established for inductors with metal and substrate loss and indicates a larger device size. The substrate and metal loss effects of inductors can be mitigated using integrated passive device (IPD) process for the input match network. The demonstrated single-band 0.18- $\mu \text{m}$ MOS LNAs with and without IPD process show noise figures of 1.53 and 2.52 dB at 2.4 GHz, respectively. Subsequently, the implemented dual-band 0.18- $\mu \text{m}$ MOS LNAs with and without IPD process show noise figures of 1.6/2.6 and 3.25/4.1 dB at 2.4/5 GHz, respectively.

Laser-drilling formation of through-glass-via (TGV) on polymer-laminated glass

A three-dimensional (3D) glass integrated passive device (IPD) is an evolutionally advanced configuration to dramatically reduce the electronics form factor and manufacturing cost of current IPDs by introducing ultra-thin glass with through-glass-vias (TGVs). A defect-free TGV formation technology in polymer-laminated glass substrates is required to realize a highly reliable 3D glass IPD. This paper discusses mechanisms of each defect formation in the use of several types of lasers to explore suitable technology for defect-free drilling in polymer-laminated glass.