Simple and Accurate Formula for the Resonant Frequency of the Circular Microstrip Disk Antenna

A simple algebraic formula for the resonant frequency of a circular microstrip disk antenna as a function of the effective radius and of the fringing capacitance has been derived which is valid for electrically-thick dielectric substrates. Accuracy of the theoretical results of resonance is compared with previous theories and measured data     

Simple and accurate formula for the resonant frequency of theequilateral triangular microstrip patch antenna

An approximate solution of the capacitance of a circular microstrip disk to account for the fringing fields is used for calculation of the resonant frequency formula of the equilateral triangular microstrip patch antenna. The theoretical results are in good agreement with experimental data     

Electronically tunable floating resistor

A new design for an electronically tunable floating resistor is proposed. The proposed circuit can be realized as a positive or negative resistor without changing the circuit topology, and can be tuned electronically. Simulation results are obtained to show adequate agreement with theory.     

Simple frequency/voltage convertor with low output ripple

A frequency/voltage convertor with theoretically zero output ripple is presented. It has a simpler structure and four times faster response than an earlier system. Moreover, it may easily be modified to a switched-capacitor version, if so desired.<>     

An arbitrary power law device based on integrators

A new simple arbitrary power law device implemented from integrators along with the sample-and-hold technique is presented. The number of the integrators indicates the index of the power law. Part of the integrators determine an appropriate time interval to be used to control the sample-and-hold circuit to extract the correct output. To test the validity and value of the proposed method, numerous power law functions have been experimented. The experimental results show very close agreement with the theoretical analysis. In addition, the measurement output, possibly as large as a few volts, is obtained with extreme precision     

Floating inductance simulation based on current conveyors

A basic floating inductance simulation circuit with grounded capacitance using only noninverting second-generation current conveyors as active elements is introduced. The circuit is modified by using current controlled conveyors, yielding electronically tunable inductances. Simulation results are also presented     

Electronically tunable multifunctional translinear-C filter andoscillator

The current-controlled second order multifunctional filter is described. It uses only three current controlled conveyors and two grounded capacitors. Three types of current transfers, highpass, bandpass, and lowpass, can be acheived simultaneously and both ω0, and Q are electronically adjustable. The circuit can also be modified to be a current controlled oscillator. The simulated results are illustrated     

Current controlled oscillator based on translinear conveyors

A current controlled oscillator based on translinear current conveyors is presented. The oscillation frequency can be varied proportionally to the bias current. The oscillator uses two CCCII's, and two grounded capacitors. SPICE simulation results agree with the theory     

Externally linear current amplifiers

This paper describes a method to implement externally linear internally non-linear (ELIN) current amplifiers. Two novel schemes of ELIN current amplifier circuits are proposed, including hyperbolic sine (SINH) and hyperbolic tangent (TANH) circuits. The obtained linear input-current ranges of SINH and TANH circuits are 400?µA_p-p with total harmonic distortion (THD) less than 2% and 140?µA_p–p with THD less than 0.2%, respectively, both at the input frequency 1?kHz. Also, the current gains of the proposed circuits can be varied either in positive or negative region by adjusting the dc bias currents. Their current gains are tunable in the range of ?10?A/A to 10?A/A and insensitive to temperature. Simulation results show that the performance of the circuits are as good as expected.