Novel design of a 2.1–2.9 GHz negative capacitance using a passive non-Foster circuit

Au, Ngoc Duc; Seo, Chulhun

doi:10.1587/elex.13.20160955

Cited by 16 publications

(16 citation statements)

References 10 publications

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“…In Au and Seo (2017), a passive non-Foster capacitance (−5 pF from 2.1 to 2.9 GHz) is reported, implemented as a -network of lumped resistors, inductors and capacitors. A negative inductance of approximately 2 nH in the same frequency range is described (Au and Seo, 2018), implemented as a dispersive transmission line. Without further proof, it can be stated that passive non-Foster implementations are intrinsically narrow band as they rely on frequency dependent, negative group delay networks, as used in the citations mentioned above.…”

Section: Realisation Of Non-foster Elementsmentioning

confidence: 99%

“…Impedance modulation is used in the uplink direction, while in the downlink, a pulse-width modulated load modulation is employed. Although just achieving a bidirectional data rate of 10 kBit s −1 , a comparable application for biomedical sensors is presented in Chen Gong et al (2017). In contrast to the latter example, frequency division multiplex is employed to transfer the up-and downlink data (binary phase shift keying (BPSK) at 2 MHz centre for energy and uplink data, also BPSK at 125 kHz for downlink data).…”

Section: Introductionmentioning

confidence: 99%

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Optimization of loosely coupled inductive data transfer systems by non-Foster impedance matching

2019

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Abstract. Wireless energy transfer is often used in industrial applications to power actors or sensors, for example in rotating applications as replacement for mechanical slip rings. In addition to the energy transfer, we have developed inductively coupled data transfer systems to expand the range of possible applications. The data transfer is accomplished by using loosely coupled coils on both sides of the power transfer system. In pure energy transfer systems, resonant coupling is used, meaning that the power transfer coils are both tuned to a common frequency to compensate the relatively small coupling factor between power transmitter and receiver and to achieve an impedance matching between both sides by compensating the inductive component of the transfer coils. In this case, capacitors can be connected in series or in parallel to the coils, leading to a sharp, narrow band resonance peak in the transfer function. In inductively coupled data transfer systems, this approach is often not useful because not just a pure sine wave has to be transferred but more likely a signal of a certain bandwidth. In one of our applications, a 100 Mbit s−1 Ethernet stream is transferred with an occupied bandwidth of 62.5 MHz. The coil structures used so far in our data transfer applications were intrinsically unmatched to the data transfer systems. Additionally, due to the small coupling factor between the data transfer coils, transfer losses in the range of up to 15 dB or worth had to be accepted. This is especially critical regarding the high noise level in vicinity of the energy transfer system and the cross coupling between the two transfer channels. For passive, lossless circuits, Foster's theorem states that the reactance increases monotonically with frequency. Subsequently, the inductive part of a circuit can just be exactly compensated with a capacitance for one single frequency. In contrast, active circuits like a negative impedance converter (NIC) can be used to achieve a non-Foster behaviour, for example a negative inductance can be realized. In theory, an inductance in series or parallel to a negative inductance of the same magnitude would be cancelled out for every frequency applied. For low power level applications like active receiving antennas, this approach has already been successfully used in the past to achieve improved matching of simple antenna structures over a comparably large bandwidth. We make use of non-Foster circuits, namely negative impedance converters, to compensate the inductive part of two loosely coupled inductors to achieve smaller transfer losses and better impedance matching, which should lead to a decreased transfer signal loss and higher signal to noise ratio. The results of this paper serve as a basis for this development. So far, we achieved almost complete cancellation of the reactive part introduced by the loosely coupled data transfer inductors. Unfortunately, the circuits active device used to form the negative impedance converter introduced a highly resistive element, greatly increasing the signal transfer losses. Nevertheless, the theory of loosely coupled inductors is shown in a compact form and a strategy to cancel the reactive part is presented. Simulations and measurements of a transfer system are carried out, both showing good agreement regarding the reactance cancellation. Based on this, optimised implementations will be developed in the future.

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Section: Realisation Of Non-foster Elementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Optimization of loosely coupled inductive data transfer systems by non-Foster impedance matching

2019

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“…Therefore, the NGD of passive NFC is not as sink as the group delay of a negative group delay network that was presented by Chaudhary [9]. Building on our previous study [6], a new passive NFC structure is proposed as shown in Fig. 2 Fig.…”

Section: Introductionmentioning

confidence: 97%

“…Previous research [6] has mentioned the relationship between phase and group delays of −5 pF. The relationship is applied to design passive NFC that does not have pure phase (phase of ideal negative lump element) and results in more loss than an ideal −5 pF capacitor because of the parasitic resonance and high passive resistor inside the circuit.…”

Section: Introductionmentioning

confidence: 99%

A design of passive negative shunt inductance circuit using negative group delay network

Seo

2018

IEICE Electron. Express

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A dispersive transmission line resonator can work in conjunction with a resistor, inductor and capacitor (RLC) circuit that can be configured to design a negative group delay (NGD) network. Furthermore, an NGD can be used as a non-Foster circuit (NFC), which can be implemented to enhance the bandwidth of some radio frequency (RF) modules. This paper discusses a dispersive short-circuit transmission line resonator as a NGD network that is used to design a passive negative shunt inductance circuit by controlling the dispersive medium of the transmission line resonator. The advantages of designing an inductance circuit this way are overcoming the power consumption problem of conventional NFCs and reducing the loss parameter caused by passive NFCs that was designed using RLC resonators.

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“…Therefore, low SA NGD circuits are essential for wireless communication. The NGD circuits have been widely used in practical applications of communication systems, such as shortening or reducing delay lines, enhancing efficiency of feedforward linear amplifier, enhancing bandwidth of feedback amplifier, minimizing beam-squint in phased array antennas systems, realization of non-Foster reactive elements [4,5,6,7,8,9,10,11,12,13,14,15].…”

Section: Introductionmentioning

confidence: 99%

A design of source-degenerated CMOS active negative group delay circuit using bonding wire

Chaudhary

Jeong

Wang

et al. 2019

IEICE Electron. Express

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This paper presents a design of CMOS source-degenerated active negative group delay (NGD) circuit by using bonding wire for a compact circuit size. The proposed circuit consists of two cascaded MOSFETs where parallel RLC resonator circuits are connected to the source of the MOSFETs. To reduce the size, the parallel RLC resonators are implemented with bonding wires and pads. For experimental verification, two-stage NGD circuits with slightly different center frequencies were designed. The measurement results show that the NGD bandwidth, group delay, and gain are 100 MHz, −2.5 ns, and 3 dB, respectively. The measured input/output return losses are higher than 8 dB and 14 dB, respectively, at the center frequency of 1.88 GHz.

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Novel design of a 2.1–2.9 GHz negative capacitance using a passive non-Foster circuit

Cited by 16 publications

References 10 publications

Optimization of loosely coupled inductive data transfer systems by non-Foster impedance matching

Optimization of loosely coupled inductive data transfer systems by non-Foster impedance matching

A design of passive negative shunt inductance circuit using negative group delay network

A design of source-degenerated CMOS active negative group delay circuit using bonding wire

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