Varactor-tunable uniplanar ring resonators

A simple and direct biomolecule detection scheme based on a microwave resonator

“…(1), n, λ g , r mean , c, f and ε eff represent the mode number of an integer, the guided wavelength, the mean radius of a ring, the speed of light, the resonant frequency and the effective relative permittivity, respectively. This is true when the mean circumference of the slot is much smaller than the height of a substrate and spacing between a ground and a signal line on a CPW [14,15]. Under these conditions, the left hand side of the Eq.…”

An X-band self-mixing oscillator antenna for transceiver and spatial power-combining applications

“…The other parameter values for the varactor diode were obtained from [6] and [10] as and . The value of is a function of the junction's reverse bias voltage and is obtained from (9) where is the junction capacitance at zero bias, is a parameter that depends on the diode doping profile, and is called the built-in potential. The values given by the manufacturer were 1 pF, 0.5 0.03, and 1.3 V, respectively.…”

“…Since the Gunn diode is capable of oscillations over a range of frequencies and the slotline antenna is by nature a broad-band device, a slotline ring resonator is added to increase the frequency stability of the circuit. The slotline ring's resonant wavelength can be determined from for (7) where is the ring's mean radius, is the guide wavelength, and is the mode number [9]. Fig.…”

Active-notch antennas stabilized with a slotline-ring resonator for wireless applications

“…where R is the mean radius of the slotline ring, g is the guide wavelength in the slotline ring, and n is the mode number [5]. A thin-wire air bridge is used to operate the CPW line in the even mode.…”