Parallel LC Tank Research Articles

An 11–40-GHz High-Power Switch With Miniaturized High-Order Topology Using 100-nm GaN-on-Si HEMTs

This article proposes an ultrawideband switch with miniaturized high-order topology. A 100-nm gate-length GaN-on-Si process is used for high-power capability, and the modeling of the GaN high-electron-mobility transistors (HEMTs) is given to analyze its parasitic values. For wideband or high isolation, the high-order switch is one solution, whose die area is naturally large. To address this issue, a miniaturized coupled-resonator switch topology was proposed using inverter transformation, where two parallel LC tanks and four inverters are replaced by two series LC tanks. Furthermore, a miniaturized coupling structure is introduced using a common inductor to replace three individual ones, contributing to an 86% size reduction. For demonstration, one 11–40.5-GHz single-pole single-throw (SPST) switch with four transmission poles (TPs) has been designed and fabricated. A small chip size of 0.32 mm2, low ON-state minimum insertion loss (IL) of 0.55 dB, and a high-power capability of 1.3 W are achieved.

Parallel resonance type fault current limiting circuit breaker

The main goal of this study is introducing a novel fault current limiter based on parallel resonance structure (PRFCL) for high voltage application. During normal mode, the PRFCL reactor is short-circuited via a rectifier bridge DC output voltage and LC resonance tank shows negligible impedance in the line. During a fault, the rectifier bridge switches are turned off, so that the parallel resonance LC tank connects to the line with high impedance. This impedance of the resonance structure can limit the fault current, successfully. It is shown that the suggested PRFCL can act as a breaker and opens the line during the fault period. In order to show the suggested PRFCL abilities, MATLAB software is used to simulate the normal and fault cases. In addition, a scale-down prototype is implemented to confirm the simulation results. The comparative study shows that PRFCL has acceptable performance in normal and current limiting operation modes.

Compact D-CRLH resonator for low-pass filter with wide rejection band, high roll-off, and transmission zeros

AbstractA compact low-pass filter (LPF) with wide rejection band based on T-type circuit of an enhanced dual composite right-/left-handed (D-CRLH) resonator is presented in this paper. The resonator has only one cell with series and parallel tank circuit. The parallel LC tank circuit has been realized by an interdigital capacitor and one shorted finger, whereas its series LC tank circuit is realized by an air gap capacitance and a short circuit stub. The filter has wide rejection band bandwidth with three transmission zeros (TZs). The filter bandwidth and TZs frequencies are controlled by the D-CRLH element values. The results of the proposed filter demonstrate minimum insertion loss in passband, high roll-off rate, and good figure of merit. The measured results are in good agreement with the simulated results. The detailed filter design is discussed in terms of circuit modeling, dispersion analysis, and full-wave simulation. Finally, the filter size is compact (0.10 λg × 0.15 λg) at cut-off frequency.

TunableQ-enhanced LC dual-band filtering at microwave frequencies in 0.13 µm SiGe BiCMOS

AbstractThis paper presents an activeQ-enhanced LC dual-band band-pass filtering approach using parallel synthesis techniques at X- and Ku-bands in 0.13µm SiGe BiCMOS technology. By employing two independently tunable parallel LC-tanks with either in-phase and out-of-phase addition, independently tunable dual-band filtering is achieved. For higher out-of-band (OOB) attenuation, subtraction of the two 2nd-order bandpass filter is implemented. The two bands are independently tunable in terms ofQand center frequency. The dual-band filter at 9.7 GHz and 13.9 GHz achieves a normalized dynamic range of 165–154.5 dB.Hz with an OOB attenuation of >50 dB below 3 GHz. In between the two bands, the attenuation is 22 dB when the two passbands have 200 MHz bandwidth each. The total group delay is 0.8 ns and 1.9 ns forQof 20 and 50, respectively. The filter achieves better OOB rejection with wider band channels at X- and Ku-bands compared with state of the art integrated filters. The filter consumes 115–130 mW of DC power. The core die area is 0.53 × 0.7 mm2.

A 2 GHz 20 dBm IIP3 Low-Power CMOS LNA with Modified DS Linearization Technique

The linearization technique for low noise amplifier (LNA) has been implemented in standard 0.18-㎛ BiCMOS process. The MOS-BJT derivative superposition (MBDS) technique exploits a parallel LC tank in the emitter of bipolar transistor to reduce the second-order non-linear coefficient (g m2 ) which limits the enhancement of linearity performance. Two feedback capacitances are used in parallel with the base-collector and gate-drain capacitances to adjust the phase of third-order non-linear coefficients of bipolar and MOS transistors to improve the linearity characteristics. The MBDS technique is also employed cascode configuration to further reduce the second-order nonlinear coefficient. The proposed LNA exhibits gain of 9.3 ㏈ and noise figure (NF) of 2.3 ㏈ at 2 ㎓. The excellent IIP3 of 20 ㏈m and low-power power consumption of 5.14 ㎽ at the power supply of 1 V are achieved. The input return loss (S 11 ) and output return loss (S 22 ) are kept below -10 ㏈ and -15 ㏈, respectively. The reverse isolation (S 12 ) is better than -50 ㏈.

A concurrent multiband CMOS low-noise amplifier for 4G standard receivers

In this article, a concurrent triple-band low-noise amplifier (LNA), which operates at 698–800, 1920–2170, and 2300–2400 MHz, is designed for long-term evolution, WCDMA/HSDPA, and Wibro services. The circuit is designed with TSMC 0.18-μm RF CMOS technology. The main topology of the proposed LNA is the cascade architecture with source degeneration. To obtain the necessary gains for this frequency bands, a series LC circuit is added in parallel with the parallel LC tank of a single-band LNA. The proposed LNA is especially suitable for use in multistandard wireless receiver front-ends as it saves die area and reduces power consumption by replacing parallel LNAs for each channel frequency. The proposed LNA has voltage gains of 14.6, 15.2, and 15.5 dB at 749, 1920, and 2300 MHz, respectively, while dissipating 7 mA from a 1.5-V supply voltage. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:834–838, 2014

Miniaturised rat‐race coupler with second and third harmonic suppression using synthesised transmission lines

A miniaturised rat-race coupler capable of suppressing the second and third harmonics is proposed. The coupler is designed with slow-wave synthesised transmission lines using two π-networks in cascade. Each π-network is formed by a parallel LC tank and two shunt capacitors, and is associated with a transmission zero for harmonic attenuation. The two transmission zeros embedded in the synthesised line can be controlled independently. The proposed rat-race coupler, centred at 2.4 GHz with an operational bandwidth of 18.8%, and at least 21-dB suppression at the second and third harmonics, features a compact footprint, which is only 12.9% the size of its conventional counterpart.

Analysis and design of a 1.8–2.7 GHz tunable 8-band TDD LTE receiver front-end

This paper describes the analysis and design of a 0.13 μm CMOS tunable receiver front-end that supports 8 TDD LTE bands, covering the 1.8–2.7 GHz frequency band and supporting the 5/10/15/20 MHz bandwidth and QPSK/16QAM/64QAM modulation schemes. The novel zero-IF receiver core consists of a tunable narrowband variable gain low-noise amplifier (LNA), a current commutating passive down-conversion mixer with a 2nd order low pass trans-impedance amplifier, an LO divider, a rough gain step variable gain pre-amplifier, a tunable 4th order Chebyshev channel select active-RC low pass filter with cutoff frequency calibration circuit and a fine gain step variable gain amplifier. The LNA can be tuned by reconfiguring the output parallel LC tank to the responding frequency band, eliminating the fixed center frequency multiple LNA array for a multi-mode receiver. The large various gain range and bandwidth of the analog baseband can also be tuned by digital configuration to satisfy the specification requirement of various bandwidth and modulation schemes. The test chip is implemented in an SMIC 0.13 μm 1P8M CMOS process. The full receiver achieves 4.6 dB NF, −14.5 dBm out of band IIP3, 30–94 dB gain range and consumes 54 mA with a 1.2 V power supply.

Dual Composite Right/Left-Handed (D-CRLH) Transmission Line Metamaterial

The novel concept of dual composite right/left-handed (D-CRLH) transmission line metamaterial is introduced. The D-CRLH is the "dual" of the conventional CRLH in the sense that it has a series parallel (instead of series) LC tank and a shunt series (instead of parallel) LC tank. This topological duality results in dual properties. The D-CRLH indeed exhibits its left-handed (LH) band at high frequencies and its right-handed (RH) band at low frequencies and is of stop-band nature, in opposition to the CRLH which is low-frequency-LH/high-frequency-RH and pass-band. The so-called balanced condition is still valid in the D-CRLH for broadband matching. However, phase origin is at dc and infinity instead, as at the LH-RH transition, and the gap between the RH and LH bands cannot be closed up in practical implementations. In contrast, the D-CRLH provides an unlimited LH bandwidth. This letter presents the homogeneous and LC-network transmission parameters and the fundamental dispersion/impedance properties of the D-CRLH

Novel VCO Architecture Using Series Above-IC FBAR and Parallel LC Resonance

A quasi-monolithic voltage-tunable film bulk acoustic resonator (FBAR) enhanced oscillator for 2.1 GHz in 0.25- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$muhbox m$</tex> SiGe BiCMOS technology is designed, fabricated, and evaluated. The narrow-band FBAR was built above the SiGe circuit through later Si post-processing steps. The oscillator is based on a two-transistor loop structure and uses two resonators, namely a parallel LC tank and an above-IC FBAR in its series-resonant mode. The improvement in phase noise performance is significant compared to a similar reference LC voltage-controlled oscillator (VCO), with the best phase noise being <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$- hbox144.1~dBc/Hz$</tex> at an offset of 1 MHz and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$- hbox149.6~dBc/Hz$</tex> at 3 MHz. The architecture offers advantages in overcoming frequency tuning difficulties usually present when using high- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q$</tex> resonators. Although the width of the tuning range comes at some cost on phase noise, the measured performance satisfies contemporary wireless standards such as GPS.

Analysis and design of LC amplifiers and LC oscillators using current-feedback amplifiers

The present paper discusses specific types of LC amplifier and LC oscillator using a current-feedback amplifier (CFA). The main advantage of the CFAs versus voltage-feedback amplifiers (VFAs) is their gain-bandwidth independence. Some of the monolithic CFAs provide an additional pin between the first stage (current-controlled current source) and the second stage (voltage follower), where the resistance is very high. This allows a parallel resonance LC tank to be connected to the additional op amp correction pin. The main advantage of this new configurations is the insignificant influence of the load over the parameters of the circuit (voltage gain, Q-factor, etc.). Some recommendations for designing this kind of analogue circuit are given, based on simulation results, symbol analysis of the transfer function and physical experiments as well as elements’ values calculation using centre frequency, voltage gain, bandwidth and Q-factor of the LC amplifiers as input parameters.

Tunable coupled inductor Q-enhancement for parallel resonant LC tanks

A tunable transformer-based Q-enhancement method for monolithic inductors used in parallel resonant LC tanks is presented. The Q of the inductor that forms the transformer primary is enhanced by cancelling the voltage drop across the series loss resistance of the primary with a voltage of opposite polarity that is induced by a current in the secondary. The circuit allows DC voltage control of Q-enhancement. Techniques to address stability issues associated with the positive feedback are described. The circuit was fabricated in 0.18 /spl mu/m CMOS and the performance was verified experimentally.

Bistability in the frequency response of a driven SQUID ring-radio frequency resonator system

We discuss the experimental observation of the frequency response of a parallel LC tank circuit inductively coupled to a SQUID ring. We show that when the rms rf flux that couples to the ring is a significant fraction of the superconducting flux quantum, Φ o (= h 2e ) , the resonance exhibits a cyclic fold bistability.

A Constant Turn-Off Time Control for Variable Frequency Thyristor Inverters

A new type of control system is described for thyristor inverters that are used to supply high-frequency power loads where the exact value of the frequency is not critical, such as for induction beating. Commutation is provided by a parallel LC tank circuit which is operated above its resonant frequency. The amount of reactive power is controlled by adjusting the actual operating frequency of the inverter. The control system is designed to maintain a constant turn-off time for each commutation every half-cycle, independent of the frequency. Also, it has a very rapid response to changes in the load conditions, thereby decreasing the chance of a commutation failure and reducing the need for additional safety margin.