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Magnetic-free non-reciprocity based on staggered commutation.

Reiskarimian N, Krishnaswamy H - Nat Commun (2016)

Bottom Line: However, they are typically bulky, expensive and not suitable for insertion in a conventional integrated circuit.Commutation is a form of parametric modulation with very high modulation ratio.We observe that staggered commutation enables time-reversal symmetry breaking within very small dimensions (λ/1,250 × λ/1,250 in our device), resulting in a miniature radio-frequency circulator that exhibits reduced implementation complexity, very low loss, strong non-reciprocity, significantly enhanced linearity and real-time reconfigurability, and is integrated in a conventional complementary metal-oxide-semiconductor integrated circuit for the first time.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Columbia University, 1300 South West Mudd, 500 West 120th Street, New York, New York 10027, USA.

ABSTRACT
Lorentz reciprocity is a fundamental characteristic of the vast majority of electronic and photonic structures. However, non-reciprocal components such as isolators, circulators and gyrators enable new applications ranging from radio frequencies to optical frequencies, including full-duplex wireless communication and on-chip all-optical information processing. Such components today dominantly rely on the phenomenon of Faraday rotation in magneto-optic materials. However, they are typically bulky, expensive and not suitable for insertion in a conventional integrated circuit. Here we demonstrate magnetic-free linear passive non-reciprocity based on the concept of staggered commutation. Commutation is a form of parametric modulation with very high modulation ratio. We observe that staggered commutation enables time-reversal symmetry breaking within very small dimensions (λ/1,250 × λ/1,250 in our device), resulting in a miniature radio-frequency circulator that exhibits reduced implementation complexity, very low loss, strong non-reciprocity, significantly enhanced linearity and real-time reconfigurability, and is integrated in a conventional complementary metal-oxide-semiconductor integrated circuit for the first time.

No MeSH data available.


Related in: MedlinePlus

Circulator S-parameter measurements.Measured circulator S-parameters (a), (d) and (g) without commutation and (b), (e) and (h) with commutation are shown, as well as (c), (f) and (i) simulated S-parameters that show an excellent match to the measurements. Under staggered commutation for clockwise circulation, low loss transmission in the circulation direction (S21, S32 and S13 are −1.7, −1.7 and −3.3 dB, respectively) and an order-of-magnitude isolation in the reverse direction (S12, S23 and S31 are −9.6, −10.4 and −17.4 dB, respectively) are measured at the commutation frequency of 750 MHz. When the third port is slightly tuned, non-reciprocity of 40–50 dB is measured in S12, S23 and S31 at 750 MHz with negligible impact on transmission in the circulation direction. The −20 dB isolation bandwidth in S31 after tuning is 32 MHz or 4.3%.
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f7: Circulator S-parameter measurements.Measured circulator S-parameters (a), (d) and (g) without commutation and (b), (e) and (h) with commutation are shown, as well as (c), (f) and (i) simulated S-parameters that show an excellent match to the measurements. Under staggered commutation for clockwise circulation, low loss transmission in the circulation direction (S21, S32 and S13 are −1.7, −1.7 and −3.3 dB, respectively) and an order-of-magnitude isolation in the reverse direction (S12, S23 and S31 are −9.6, −10.4 and −17.4 dB, respectively) are measured at the commutation frequency of 750 MHz. When the third port is slightly tuned, non-reciprocity of 40–50 dB is measured in S12, S23 and S31 at 750 MHz with negligible impact on transmission in the circulation direction. The −20 dB isolation bandwidth in S31 after tuning is 32 MHz or 4.3%.

Mentions: S-parameter measurements of the three-port circulator were performed using a measurement setup described in the Methods section. In the absence of commutation, with a pair of transistor switches on either side of the capacitor bank permanently closed, the circuit is perfectly reciprocal (Fig. 7a,d,g). In this configuration the high reciprocal isolations from port 3 to ports 1 and 2 are seen because port 3 is shunted to ground by one of the 26-pF capacitors. The quarter-wave transmission lines from port 1 to the staggered commutated network and from port 2 to port 3 transform this near-short-circuit impedance to open circuits at ports 1 and 2, effectively disconnecting port 3 from the rest of the circuit and resulting in a reciprocal structure that exhibits low-loss transmission between port 1 and port 2. Similarly, another reciprocal configuration without commutation is depicted, where all switches are permanently open. Here, simple circuit analysis reveals that port 1 is effectively disconnected from the rest of the circuit, which now exhibits low-loss reciprocal transmission between ports 2 and 3.


Magnetic-free non-reciprocity based on staggered commutation.

Reiskarimian N, Krishnaswamy H - Nat Commun (2016)

Circulator S-parameter measurements.Measured circulator S-parameters (a), (d) and (g) without commutation and (b), (e) and (h) with commutation are shown, as well as (c), (f) and (i) simulated S-parameters that show an excellent match to the measurements. Under staggered commutation for clockwise circulation, low loss transmission in the circulation direction (S21, S32 and S13 are −1.7, −1.7 and −3.3 dB, respectively) and an order-of-magnitude isolation in the reverse direction (S12, S23 and S31 are −9.6, −10.4 and −17.4 dB, respectively) are measured at the commutation frequency of 750 MHz. When the third port is slightly tuned, non-reciprocity of 40–50 dB is measured in S12, S23 and S31 at 750 MHz with negligible impact on transmission in the circulation direction. The −20 dB isolation bandwidth in S31 after tuning is 32 MHz or 4.3%.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835534&req=5

f7: Circulator S-parameter measurements.Measured circulator S-parameters (a), (d) and (g) without commutation and (b), (e) and (h) with commutation are shown, as well as (c), (f) and (i) simulated S-parameters that show an excellent match to the measurements. Under staggered commutation for clockwise circulation, low loss transmission in the circulation direction (S21, S32 and S13 are −1.7, −1.7 and −3.3 dB, respectively) and an order-of-magnitude isolation in the reverse direction (S12, S23 and S31 are −9.6, −10.4 and −17.4 dB, respectively) are measured at the commutation frequency of 750 MHz. When the third port is slightly tuned, non-reciprocity of 40–50 dB is measured in S12, S23 and S31 at 750 MHz with negligible impact on transmission in the circulation direction. The −20 dB isolation bandwidth in S31 after tuning is 32 MHz or 4.3%.
Mentions: S-parameter measurements of the three-port circulator were performed using a measurement setup described in the Methods section. In the absence of commutation, with a pair of transistor switches on either side of the capacitor bank permanently closed, the circuit is perfectly reciprocal (Fig. 7a,d,g). In this configuration the high reciprocal isolations from port 3 to ports 1 and 2 are seen because port 3 is shunted to ground by one of the 26-pF capacitors. The quarter-wave transmission lines from port 1 to the staggered commutated network and from port 2 to port 3 transform this near-short-circuit impedance to open circuits at ports 1 and 2, effectively disconnecting port 3 from the rest of the circuit and resulting in a reciprocal structure that exhibits low-loss transmission between port 1 and port 2. Similarly, another reciprocal configuration without commutation is depicted, where all switches are permanently open. Here, simple circuit analysis reveals that port 1 is effectively disconnected from the rest of the circuit, which now exhibits low-loss reciprocal transmission between ports 2 and 3.

Bottom Line: However, they are typically bulky, expensive and not suitable for insertion in a conventional integrated circuit.Commutation is a form of parametric modulation with very high modulation ratio.We observe that staggered commutation enables time-reversal symmetry breaking within very small dimensions (λ/1,250 × λ/1,250 in our device), resulting in a miniature radio-frequency circulator that exhibits reduced implementation complexity, very low loss, strong non-reciprocity, significantly enhanced linearity and real-time reconfigurability, and is integrated in a conventional complementary metal-oxide-semiconductor integrated circuit for the first time.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Columbia University, 1300 South West Mudd, 500 West 120th Street, New York, New York 10027, USA.

ABSTRACT
Lorentz reciprocity is a fundamental characteristic of the vast majority of electronic and photonic structures. However, non-reciprocal components such as isolators, circulators and gyrators enable new applications ranging from radio frequencies to optical frequencies, including full-duplex wireless communication and on-chip all-optical information processing. Such components today dominantly rely on the phenomenon of Faraday rotation in magneto-optic materials. However, they are typically bulky, expensive and not suitable for insertion in a conventional integrated circuit. Here we demonstrate magnetic-free linear passive non-reciprocity based on the concept of staggered commutation. Commutation is a form of parametric modulation with very high modulation ratio. We observe that staggered commutation enables time-reversal symmetry breaking within very small dimensions (λ/1,250 × λ/1,250 in our device), resulting in a miniature radio-frequency circulator that exhibits reduced implementation complexity, very low loss, strong non-reciprocity, significantly enhanced linearity and real-time reconfigurability, and is integrated in a conventional complementary metal-oxide-semiconductor integrated circuit for the first time.

No MeSH data available.


Related in: MedlinePlus