scholarly journals All-Pass Filter Based Linear Voltage Controlled Quadrature Oscillator

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Koushick Mathur ◽  
Palaniandavar Venkateswaran ◽  
Rabindranath Nandi
Keyword(s):  
Current Feedback ◽  
Pass Filter ◽  
Quadrature Oscillator ◽  
First Order ◽  
Feedback Amplifier ◽  
Current Feedback Amplifier ◽  
Control Node ◽  
Node Voltage ◽  
Electronically Tunable ◽  
Linear Voltage

A linear voltage controlled quadrature oscillator implemented from a first-order electronically tunable all-pass filter (ETAF) is presented. The active element is commercially available current feedback amplifier (AD844) in conjunction with the relatively new Multiplication Mode Current Conveyor (MMCC) device. Electronic tunability is obtained by the control node voltage (V) of the MMCC. Effects of the device nonidealities, namely, the parasitic capacitors and the roll-off poles of the port-transfer ratios of the device, are shown to be negligible, even though the usable high-frequency ranges are constrained by these imperfections. Subsequently the filter is looped with an electronically tunable integrator (ETI) to implement the quadrature oscillator (QO). Experimental responses on the voltage tunable phase of the filter and the linear-tuning law of the quadrature oscillator up to 9.9 MHz at low THD are verified by simulation and hardware tests.

scholarly journals Electronically Tunable Differential Integrator: Linear Voltage Controlled Quadrature Oscillator

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Rabindranath Nandi ◽  
Sandhya Pattanayak ◽  
Palaniandavar Venkateswaran ◽  
Sagarika Das
Keyword(s):  
Building Block ◽  
Phase Error ◽  
Control Voltage ◽  
Current Feedback ◽  
Quadrature Oscillator ◽  
Active Devices ◽  
Feedback Amplifier ◽  
Current Feedback Amplifier ◽  
Electronically Tunable ◽  
Double Integrator

A new electronically tunable differential integrator (ETDI) and its extension to voltage controlled quadrature oscillator (VCQO) design with linear tuning law are proposed; the active building block is a composite current feedback amplifier with recent multiplication mode current conveyor (MMCC) element. Recently utilization of two different kinds of active devices to form a composite building block is being considered since it yields a superior functional element suitable for improved quality circuit design. The integrator time constant (τ) and the oscillation frequency (ωo) are tunable by the control voltage (V) of the MMCC block. Analysis indicates negligible phase error (θe) for the integrator and low active ωo-sensitivity relative to the device parasitic capacitances. Satisfactory experimental verifications on electronic tunability of some wave shaping applications by the integrator and a double-integrator feedback loop (DIFL) based sinusoid oscillator with linear fo variation range of 60 KHz~1.8 MHz at low THD of 2.1% are verified by both simulation and hardware tests.

scholarly journals Design Impedance Mismatch Physical Unclonable Functions for IoT Security

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaomin Zheng ◽  
Yuejun Zhang ◽  
Jiaweng Zhang ◽  
Wenqi Hu
Keyword(s):  
Transmission Line ◽  
Printed Circuit Board ◽  
Signal Transmission ◽  
Characteristic Impedance ◽  
Circuit Board ◽  
Physical Factors ◽  
Current Feedback ◽  
Impedance Mismatch ◽  
Feedback Amplifier ◽  
Current Feedback Amplifier

We propose a new design, Physical Unclonable Function (PUF) scheme, for the Internet of Things (IoT), which has been suffering from multiple-level security threats. As more and more objects interconnect on IoT networks, the identity of each thing is very important. To authenticate each object, we design an impedance mismatch PUF, which exploits random physical factors of the transmission line to generate a security unique private key. The characteristic impedance of the transmission line and signal transmission theory of the printed circuit board (PCB) are also analyzed in detail. To improve the reliability, current feedback amplifier (CFA) method is applied on the PUF. Finally, the proposed scheme is implemented and tested. The measure results show that impedance mismatch PUF provides better unpredictability and randomness.

SINGLE CFA-BASED NICs WITH IMPEDANCE SCALING PROPERTIES

2005 ◽  
Vol 14 (02) ◽  
pp. 195-203 ◽  
Author(s):  
ALI ÜMIT KESKIN
Keyword(s):  
Integrated Circuits ◽  
Mixed Mode ◽  
Building Blocks ◽  
Current Feedback ◽  
Scaling Properties ◽  
Feedback Amplifier ◽  
Current Feedback Amplifier ◽  
Design And Manufacturing ◽  
Impedance Scaling ◽  
Impedance Converter

Negative impedance converter circuits (NICs) are important building blocks in design and manufacturing of analog and mixed mode integrated circuits. In this paper, a catalogue of single-current feedback amplifier-based negative impedance converter circuits having impedance scaling properties is proposed. Various examples are presented to illustrate the versatility of the proposed NIC circuits.

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