“…The input reflection into an ideal NRPS, where the load reflection coefficient is denoted by as shown in Fig. 2 a, was given in 23 by The interpretation of ( 2 ) is that ideal NRPS circuits are effectively transparent, and the input impedance equals the output impedance, as illustrated in Fig. 2 b.…”
Section: Network Properties Of the
Non-reciprocal Phase Shi...mentioning
confidence: 99%
“…The latter utilizes a cascade of a PS and a NRPS that results in a virtual ground over the switches of the N-path NRPS for input signals at port 1, which is an advantage over the circulators of 15 and 16 that allow large signal swing over the NRPS and hence are less linear 22 . In 23 , a quasi-circulating quadrature hybrid (QCQH) was described similar to the circulators of 19 , 20 but with a fourth port added at the other terminal of the NRPS, as shown in Fig. 1 f. Figure 1 Seven decades of non-reciprocal devices: ( a ) gyrator—non-reciprocal phase shifter (NRPS) that introduces a phase difference for signals propagating in opposite directions.…”
Section: Introductionmentioning
confidence: 99%
“…( e ) ring circulator with two PS arms and a NRPS based on a PS in series with a NRPS 19 , 20 and 21 . f quasi circulating quadrature hybrid (QCQH) 23 . …”
Section: Introductionmentioning
confidence: 99%
“…In work 27 , a four-port circulating duplexer was proposed. It comprised a QCQH 23 and a commercial quadrature hybrid (QH). Cascading ports 3 and 4 of a QCQH with a QH result in S-parameters approximating a four-port circulator when implemented with an ideal NRPS 27 .…”
This paper presents a family of four-port electronic circulators adhering to a new topology symmetry that enables linear, low-loss transistor-based circuit implementations. The underlying principle of operation employs a property of the $$90^\circ $$
90
∘
non-reciprocal phase shifter (NRPS) derived in this article. Under quadrature excitation, the NRPS transfers or reflects exciting signals depending on their respective phase lead. The fundamental topology consists of two back-to-back quadrature hybrid couplers with a $$90^\circ $$
90
∘
NRPS connected in parallel over the line of symmetry, interrupting the circuit’s reciprocity to achieve circular propagation by bypassing or reflecting at the NRPS but not through. We break down the circuit into three fundamental four-port sub-circuits. The transfer function of the cascaded sub-circuits enables an analysis with specific hybrid couplers. It also allows a synthesis of other four-port passive sub-circuits that, with an NRPS, achieve a four-port circulator transfer function by solving a matrix equation. Some of the mathematical solutions have circuit realizations, which are adjusted quadrature hybrid structures that differ from each other by the characteristic impedance of their arms. Two familiar solutions, including the standard quadrature hybrid and a modified design with equal $$Z_0$$
Z
0
, $$\lambda /4$$
λ
/
4
arms, are simulated utilizing lossless lumped element arms and a 4-Path, 65-nm NMOS $$90^\circ $$
90
∘
NRPS. The simulation results verify the theoretical analysis and enable a comparison between the performance of the two circuit solutions around 1 GHz. The four-port circulator with equal arms is implemented on a PCB and measured, yielding better than 1.5 dB insertion loss between the circulator ports, over 17 dB port-to-port reverse isolation, and better than 20 dBr port matching around 1 GHz.
“…The input reflection into an ideal NRPS, where the load reflection coefficient is denoted by as shown in Fig. 2 a, was given in 23 by The interpretation of ( 2 ) is that ideal NRPS circuits are effectively transparent, and the input impedance equals the output impedance, as illustrated in Fig. 2 b.…”
Section: Network Properties Of the
Non-reciprocal Phase Shi...mentioning
confidence: 99%
“…The latter utilizes a cascade of a PS and a NRPS that results in a virtual ground over the switches of the N-path NRPS for input signals at port 1, which is an advantage over the circulators of 15 and 16 that allow large signal swing over the NRPS and hence are less linear 22 . In 23 , a quasi-circulating quadrature hybrid (QCQH) was described similar to the circulators of 19 , 20 but with a fourth port added at the other terminal of the NRPS, as shown in Fig. 1 f. Figure 1 Seven decades of non-reciprocal devices: ( a ) gyrator—non-reciprocal phase shifter (NRPS) that introduces a phase difference for signals propagating in opposite directions.…”
Section: Introductionmentioning
confidence: 99%
“…( e ) ring circulator with two PS arms and a NRPS based on a PS in series with a NRPS 19 , 20 and 21 . f quasi circulating quadrature hybrid (QCQH) 23 . …”
Section: Introductionmentioning
confidence: 99%
“…In work 27 , a four-port circulating duplexer was proposed. It comprised a QCQH 23 and a commercial quadrature hybrid (QH). Cascading ports 3 and 4 of a QCQH with a QH result in S-parameters approximating a four-port circulator when implemented with an ideal NRPS 27 .…”
This paper presents a family of four-port electronic circulators adhering to a new topology symmetry that enables linear, low-loss transistor-based circuit implementations. The underlying principle of operation employs a property of the $$90^\circ $$
90
∘
non-reciprocal phase shifter (NRPS) derived in this article. Under quadrature excitation, the NRPS transfers or reflects exciting signals depending on their respective phase lead. The fundamental topology consists of two back-to-back quadrature hybrid couplers with a $$90^\circ $$
90
∘
NRPS connected in parallel over the line of symmetry, interrupting the circuit’s reciprocity to achieve circular propagation by bypassing or reflecting at the NRPS but not through. We break down the circuit into three fundamental four-port sub-circuits. The transfer function of the cascaded sub-circuits enables an analysis with specific hybrid couplers. It also allows a synthesis of other four-port passive sub-circuits that, with an NRPS, achieve a four-port circulator transfer function by solving a matrix equation. Some of the mathematical solutions have circuit realizations, which are adjusted quadrature hybrid structures that differ from each other by the characteristic impedance of their arms. Two familiar solutions, including the standard quadrature hybrid and a modified design with equal $$Z_0$$
Z
0
, $$\lambda /4$$
λ
/
4
arms, are simulated utilizing lossless lumped element arms and a 4-Path, 65-nm NMOS $$90^\circ $$
90
∘
NRPS. The simulation results verify the theoretical analysis and enable a comparison between the performance of the two circuit solutions around 1 GHz. The four-port circulator with equal arms is implemented on a PCB and measured, yielding better than 1.5 dB insertion loss between the circulator ports, over 17 dB port-to-port reverse isolation, and better than 20 dBr port matching around 1 GHz.
“…All kinds of components and circuits are playing an important role in the wireless personal communications systems [1][2]. In recent years, various kinds of filters, circulators and power dividers [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] have been studied. Such as: broadband active quasi-circulator operating in UHF and L-band [5]，compact active three-way circulators [6,7]， integratable active quasi-circulator [8,9,10]，low-loss hexagonal ferrite self-biasing microstrip and CPW circulators [11]， self-biased CPW circulator for Ku-Band [12], an X-Band quasi-circulator with GaAs MMIC [13], quasi-circulator with extra large isolation [14], a CMOS active quasi-circulator with a built-in rectifier [15], high-bandwith quasi-circulator [16,17,18], active three-way circulator using transistor feedback network [19], broadband eight-way differential SIW power divider [20].…”
An active quasi-circulator based on Wilkinson power divider has been proposed and analyzed in this paper. A power divider, two common-source connected transmits and receive transistor amplifiers are used to consist of the circuit. The single conductivity of the transistor and the isolation of the power divider's isolation resistor are used to eliminate the interference between the received and transmitted signals, thus achieving the role of the quasi-circulator. The advantage of this circuit is that the received and transmitted electromagnetic signals can be amplified by two transistor amplifiers to a certain extent, which can save the design of additional signal power amplification circuits and improve the efficiency of circuit design. In order to verify the effectiveness of the proposed structure, an active quasi-circulator with a frequency band of 5GHz-6GHz is designed and the simulated structure is machined and fabricated. According to the measured results, in the frequency band of 5GHz-6GHz, the input return loss of antenna port is lower than − 10dB, the output return loss of transmit and receive ports are lower than − 15dB, and the degree of isolation between receive and transmit branches of the quasi-circulator is lower than − 18.6dB, which shows that the quasi-circulator has good working characteristics.
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