Microstrip Fano resonator switch

Patent metadata

Field	Value
Publication number	US-10186744-B2
Application number	US-201715425997-A
Country	US
Kind code	B2
Filing date	Feb 6, 2017
Priority date	Feb 6, 2017
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

The microstrip Fano resonator switch is a microstrip circuit having a varactor diode electrically connected between identical quarter-wavelength open stubs formed from two elongate planar strip elements disposed on a substrate having a permittivity of approximately 2.94 and a thickness of approximately 0.76 mm, the circuit forming a Fano resonator switch that provides approximately 50 dB of isolation.

First claim

We claim:

1. A microstrip Fano resonator switch, comprising:
a non-conducting substrate;
a rectangular conducting transmission strip disposed on the non-conducting substrate;
first and second substantially identically dimensioned rectangular conducting stubs disposed on the non-conducting substrate in parallel relation and in close proximity to each other and in perpendicular relation to the conducting transmission strip, the stubs being electrically connected to and extending from the transmission strip, the stubs having open ends distal from the conducting transmission strip; and
a capacitance disposed proximate the stub open ends and electrically connected to the stub open ends;
wherein, the transmission strip and the capacitive open stubs in close proximity to each other form a Fano resonator having a switching frequency that induces in-phase electromagnetic fields which interfere constructively to suppress transmission via the transmission strip at the switching frequency.

2. The microstrip Fano resonator switch according to claim 1 , wherein the switch has a modulating asymmetric Fano function σ a (ω) characterized by:

σ
a

⁡

(
ω
)

=

(

ω
2

-

ω
a
2

(

Δ
⁢

⁢

ω
a

+

ω
a

)

2

-

ω
a
2

+
q

)

2

+
b

(

ω
2

-

ω
a
2

(

Δ
⁢

⁢

ω
a

+

ω
a

)

2

-

ω
a
2

)

2

+
1

,

where ω a , Δω a , q, and b are parameters representing a resonance frequency position, a spectral bandwidth, an asymmetry parameter, and a loss due to intrinsic losses, respectively.

3. The microstrip Fano resonator switch according to claim 1 , wherein the capacitance is a varactor diode having a variable capacitance tuning the frequency response of the Fano resonator switch.

4. The microstrip Fano resonator switch according to claim 3 , wherein the switching frequency is 1.48 GHz, so that a change of 0.1 pF in the variable capacitance of the varactor diode results in 50 dB isolation between ‘on’ and ‘off’ states of the Fano resonator switch.

5. The microstrip Fano resonator switch according to claim 1 , wherein the substrate has a permittivity of approximately 2.94.

6. The microstrip Fano resonator switch according to claim 1 , wherein the substrate has a thickness of approximately 0.76 mm.

7. The microstrip Fano resonator switch according to claim 1 , wherein the switch has a symmetric background resonance characterized by:

R
b

⁡

(
ω
)

=

a
2

(

ω
2

-

ω
s
2

(

Δ

Assignees

• Univ United Arab Emirates

Inventors

• Ramzan Rashad
• Amin Muhammad
• Siddiqui Omar Farooq
• Bastaki Nabil

Classifications

• H01P7/08

  Strip line resonators · CPC title

• H01P3/08

  Microstrips; Strip lines · CPC title

• H01P1/203 Primary

  Strip line filters · CPC title

• H01P1/127

  Strip line switches · CPC title

• H01P7/082 Primary

  Microstripline resonators (H01P7/088 takes precedence) · CPC title