Passive Device Technology Research Articles

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.

IPD bandpass filter chip based on the filter prototype realized by new compact resonators

In this paper, a resonator based on a coupled inductor and a capacitor is proposed to obtain a pole and a zero concurrently. This resonator has a compact layout with a size of only an inductor. This paper describes the idea of constructing filter circuit completely based on this type of resonator and presents a method to realize the equivalence between networks of the resonators and classical filter prototypes. Bandpass filters based on the resonators can be realized to verify the feasibility of the method. A filter chip with a size of 2.01 × 1.21 mm2 is realized by the integrated passive device (IPD) technology. The operation frequency with |S11| < −10 dB and |S22| < −10 dB covers 4.93–6.15 GHz, two out-of-band poles are 0.87 GHz and 0.45 GHz away from the passband edges respectively, the measured insertion loss is 2.04 dB.

Ultra wideband lumped Wilkinson power divider on gallium arsenide integrated passive device technology

In this letter, a novel lumped Wilkinson power divider (WPD) introducing capacitors on the isolation R of ultra wideband with good isolation and insertion loss (IL) performance is proposed with the help of gallium arsenide (GaAs) technology. With the even and odd method, the proposed WPD is better illustrated. The fractional bandwidth (FBW) is 104% (3–9.5 GHz). Besides, the return loss is better than 13.7 dB, and the IL is better than 0.62 dB within the passband. The isolation is better than 19.5 dB from 3 to 9.5 GHz. Finally, to better illustrate the design conception, it has been fabricated on GaAs integrated passive device technology with size of 1.37 × 0.971 mm2, that is, 0.1 × 0.072 λg2, measured by on-wafer probing. All the final results of the proposed WPD are reasonably matched well.

Design of Low Pass Filter using Passive Inductor

This paper discusses the passive inductor-based low pass filter (LPF) up to 1.144 GHz bandwidth range with the use of integrated passive device (IPD) technology. In this circuit, three MIM capacitors and three inductors are added parallel to create transmission zeros at a frequency of about 2.2 GHz and 3.6 GHz. The filter has been designed by this method with less structure complexity, a small insertion loss, a small chip area, increase bandwidth, and high out-of-band rejection. After the fabrication of the low pass filter circuit, the insertion loss of 0.7 dB, center frequency 600 MHz, and harmonic rejections of 62 dB with the chip area of 1125.21 μm×471.25 μm including pads.

Creating distinctive connections between multifunctional microwave circuits and mobile-terminal radio-frequency integrated chips using integrated passive device technology

In this review, the advanced microwave devices based on the integrated passive device (IPD) technology are expounded and discussed in detail, involving the performance breakthroughs and circuit innovations. Then, the development trend of IPD-based multifunctional microwave circuits is predicted further by analyzing the current research hot spots. This paper discusses a distinctive research area for microwave circuits and mobile-terminal radio-frequency integrated chips.

Microwave humidity sensor based on carbon dots-decorated MOF-derived porous Co3O4 for breath monitoring and finger moisture detection

This research investigates a microwave transduction-based humidity sensor that is a promising candidate for real-time clinical healthcare applications and green miniaturized wearable electronic devices. Optimization of sensing material, sensing platform, and device fabrication techniques produces a carbon dots (CDs)-decorated metal organic framework (MOF)-derived porous Co3O4 (CDs-Co3O4) microwave resonator-based sensor with excellent real-time humidity detection. Inspired by the water absorption component polyacrylamide in baby diapers, the acrylamide is adopted to synthesize CDs for microwave humidity sensor. Combining CDs with MOF-derived porous Co3O4 enhances humidity sensitivity under microwave excitation, with a frequency shift of 3.40 MHz/% RH and a loss variation of 0.15 dB/% RH between 5% and 99% RH. These values are 49.7% (for frequency shift) and 20.5% (for return loss) higher than Co3O4 sensor. Moreover, CDs-Co3O4 exhibits high selectivity towards water vapor against other volatile organic compounds, and the response or recovery time are both less than 5 s. Fabricated by an integrated passive device technology, the sensing platform is miniaturized at 0.98 × 0.80 × 0.22 mm3 with superb device stability and reliability. The CDs-Co3O4 sensor remarkably monitors respiratory patterns of breathing or apnea, as well as subtle changes in the humidity levels of an approaching finger. A charge transfer process and microwave interactions are the mechanisms for improved humidity sensitivity.

A W-Band 1-dB Insertion Loss Wilkinson Power Divider Using Silicon-Based Integrated Passive Device

This work presents an on-chip Wilkinson power divider using silicon-based integrated passive device (IPD) technology that operates from 70 to 110 GHz, thereby covering the entire W-band (75-110 GHz). Based on a simple impedance transformation different from the conventional Wilkinson power divider topology, the proposed silicon IPD power divider with a core size of 0.417 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> can demonstrate power loss of less than 1.1 dB along with input-output return loss better than 14 dB throughout the entire band.

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.

Millimeter-Wave Dual-Band Bandpass Filter With Large Bandwidth Ratio Using GaAs-Based Integrated Passive Device Technology

In this letter, a millimeter-wave (mm-wave) dual-band bandpass filter is proposed with large bandwidth ratio by using gallium arsenide (GaAs)-based integrated passive device (IPD) technology. To realize small chip size, one dual-mode on-chip resonator is designed by using quasi-lumped capacitors and microstrip lines. In addition, multiple transmission zeroes are generated by further introducing both the electric and magnetic couplings between adjacent resonators. To realize large bandwidth ratio of two passbands, the external quality factors are investigated at both passband, and can be independently controlled. For demonstration, a 28-/50-GHz dual-band bandpass filter is designed, fabricated, and measured. The fractional bandwidth ratio is 7.8, which is much larger than the reported on-chip filters. Meanwhile, very low insertion loss of 0.58-dB is realized for the lower passband at 28 GHz, indicating the proposed dual-band bandpass filter a promising application in mm-wave wireless systems.

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.

Ultra-Miniaturized Wideband Input-Absorptive Bandstop Filter Based on TFIPD Technology

This brief presents the ultra-miniaturized wideband input-absorptive bandstop filters with one and three transmission zeros using the thin film integrated passive devices (TFIPD) technology. It is based on a novel T-shape structure with lumped-element resonators and one resistor chained on the input port. The basic bandstop block composed of lumped-element resonators can be synthesized by the Chebyshev reflective prototype values ( g-parameters). In order to further expand the stopband bandwidth and improve the frequency selectivity, the series inductance and capacitance resonator (SICR) is loaded on the basic bandstop block, thus resulting in two extra transmission zeros. The chained resistor on the input port is used to absorb the input-signal power. For demonstration, the one-zero and three-zero design cases operating at 5 GHz are simulated, manufactured and measured, respectively.

IPD capacitor with pseudo-symmetry for isolated differential signal transfer applications

In this paper, capacitors fabricated by an integrated passive device technology for isolated signal transfer applications are presented. The shapes of the capacitor plates are designed to achieve a symmetrical capacitive coupling matrix. Without using any highly doped shielding layer, the interference through the substrate can be eliminated in both forward and reverse directions for differential isolated signal transfer, regardless of the waveforms of the transmitter circuit. An isolation capacitor array with 3 channels and 700 ​fF capacitance values is experimentally demonstrated using a multilayer Cu/polyimide process. The capacitors show accurate capacitance values, 5kVrms isolation voltage and low leakage current of tens of pA at working voltage. Measurement results also show that the capacitor array with pseudo-symmetry reduces the mismatched interference signal by 5 times.

Ultra-compact wideband dual-mode Wilkinson power divider based on thin film integrated passive device fabrication technology

ABSTRACT This paper presents an ultra-wideband and highly miniaturized dual-mode Wilkinson power divider fabricated using thin film integrated passive device (TFIPD) technology for GSM band (0.9 GHz). The four quarter-wavelength lines of conventional two-section Wilkinson power divider are replaced with π-type transformer. In addition, a RC filter is introduced at the input port to minimize the return loss. The presented power divider prototype is micro-fabricated on a gallium arsenide (GaAs) substrate through TFIPD technology to reduce overall structure size and minimize overall parasitic losses. The fabricated power divider exhibits compact size at central frequency of 0.9 GHz with an ultra-wideband working bandwidth. To the best of authors’ knowledge, the designed power divider is approximately 8 times smaller than the previously reported power dividers.

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.

A Novel Miniature Dual-Band Impedance Matching Network for Frequency-Dependent Complex Impedances

In this article, a novel dual-band impedance matching network capable of providing impedance matching between frequency-dependent complex impedances at two frequencies is reported. The proposed dual-band impedance matching network employs the dual-band design of bridged-T coil, such that a very compact circuit size and dual-band operation can be achieved at the same time. Various design examples are presented to demonstrate the versatile property of the proposed dual-band impedance matching network, along with a rigorous analysis of its practical limitations. Also, two design examples of the proposed dual-band impedance matching network are implemented using the integrated passive device technology for performance validation.

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.

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.

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.