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New quartz oscillator switching method for nano-Henry range inductance measurements.

Matko V, Jezernik K - Sensors (Basel) (2012)

Bottom Line: The real novelty of this method, however, lies in a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 0 °C and 50 °C through a switching method which compensates for the crystal's natural temperature characteristics.This allows for the compensation of any influences on the crystal such as the compensation of the non-linear temperature characteristics and the ageing of both the crystal and other oscillating circuit elements, as well as the reduction of the output frequency measurement errors with the help of an additional reference frequency.The experimental results show that the switching method greatly improves the measurement of small inductance changes in the range between μH and nH, allowing as a result high-precision measurements (~0.35 fH) in this range.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia. karel.jezernik@uni-mb.si

ABSTRACT
This article introduces a new method for nano-Henry inductance measurements at the frequency of 4.999 MHz with a single quartz crystal oscillating in the switching oscillating circuit. The real novelty of this method, however, lies in a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 0 °C and 50 °C through a switching method which compensates for the crystal's natural temperature characteristics. This allows for the compensation of any influences on the crystal such as the compensation of the non-linear temperature characteristics and the ageing of both the crystal and other oscillating circuit elements, as well as the reduction of the output frequency measurement errors with the help of an additional reference frequency. The experimental results show that the switching method greatly improves the measurement of small inductance changes in the range between μH and nH, allowing as a result high-precision measurements (~0.35 fH) in this range.

No MeSH data available.


Dual switching mode oscillator.
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f1-sensors-12-03105: Dual switching mode oscillator.

Mentions: A dual switching mode oscillator is based on one quartz crystal and a dual oscillator circuit with switching part together (Figure 1) [1,14,19]. The switching between the frequencies fo1 and fo2 is done by an additional switching frequency (Sync) of 1 Hz and an additional circuit of three NAND gates. Inductances Lm1 and Lm2 can also be used as sensors in differential mode. Inductors can be produced in various standard forms. They can generally be classified as strip inductors or spiral inductors. Straight sections of wires or strip are used for low inductance values, typically less than 10 nH, while spiral have higher quality Qs and can provide higher inductance values. The presence of a ground plane also affects the inductance. The inductance decreases when the ground plane is brought nearer to the conducting line. Planar inductors are made essentially with a single-layer metallization scheme, in which a conducting layer is etched on a dielectric substrate. In the experiment, Lm1 consists of two inductances in the series—standard element (123 μH) and straight sections of strip for low inductance values (2 nH) (etched on Al2O3). The inductance of a strip line can be written as [26–31]:(1)Lstraight=2l[ln(lw+t)+0.22w+tl+1.19]Where Lstraight is the segment inductance in nH, l = 0.5 cm, w = 0.05 cm, and t = 0.05 cm are the segment length, width and thickness, respectively. By changing the length l (using constant values), inductance values of Lstraight in the range between 0 and 2 nH can be set. Inductance Lstraight was measured by a HP 4194A impedance/gain-phase analyzer. Inductance Lm2 has the value of 123 μH. The basic values of inductances Lm1 and Lm2 are determined with the compensation criterion (Equation (2)) in relation to the parasitic capacitance Co = 8 pF of the quartz crystal [1,8,19,26]:(2)k⋅Lm=1/k⋅C0


New quartz oscillator switching method for nano-Henry range inductance measurements.

Matko V, Jezernik K - Sensors (Basel) (2012)

Dual switching mode oscillator.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376594&req=5

f1-sensors-12-03105: Dual switching mode oscillator.
Mentions: A dual switching mode oscillator is based on one quartz crystal and a dual oscillator circuit with switching part together (Figure 1) [1,14,19]. The switching between the frequencies fo1 and fo2 is done by an additional switching frequency (Sync) of 1 Hz and an additional circuit of three NAND gates. Inductances Lm1 and Lm2 can also be used as sensors in differential mode. Inductors can be produced in various standard forms. They can generally be classified as strip inductors or spiral inductors. Straight sections of wires or strip are used for low inductance values, typically less than 10 nH, while spiral have higher quality Qs and can provide higher inductance values. The presence of a ground plane also affects the inductance. The inductance decreases when the ground plane is brought nearer to the conducting line. Planar inductors are made essentially with a single-layer metallization scheme, in which a conducting layer is etched on a dielectric substrate. In the experiment, Lm1 consists of two inductances in the series—standard element (123 μH) and straight sections of strip for low inductance values (2 nH) (etched on Al2O3). The inductance of a strip line can be written as [26–31]:(1)Lstraight=2l[ln(lw+t)+0.22w+tl+1.19]Where Lstraight is the segment inductance in nH, l = 0.5 cm, w = 0.05 cm, and t = 0.05 cm are the segment length, width and thickness, respectively. By changing the length l (using constant values), inductance values of Lstraight in the range between 0 and 2 nH can be set. Inductance Lstraight was measured by a HP 4194A impedance/gain-phase analyzer. Inductance Lm2 has the value of 123 μH. The basic values of inductances Lm1 and Lm2 are determined with the compensation criterion (Equation (2)) in relation to the parasitic capacitance Co = 8 pF of the quartz crystal [1,8,19,26]:(2)k⋅Lm=1/k⋅C0

Bottom Line: The real novelty of this method, however, lies in a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 0 °C and 50 °C through a switching method which compensates for the crystal's natural temperature characteristics.This allows for the compensation of any influences on the crystal such as the compensation of the non-linear temperature characteristics and the ageing of both the crystal and other oscillating circuit elements, as well as the reduction of the output frequency measurement errors with the help of an additional reference frequency.The experimental results show that the switching method greatly improves the measurement of small inductance changes in the range between μH and nH, allowing as a result high-precision measurements (~0.35 fH) in this range.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia. karel.jezernik@uni-mb.si

ABSTRACT
This article introduces a new method for nano-Henry inductance measurements at the frequency of 4.999 MHz with a single quartz crystal oscillating in the switching oscillating circuit. The real novelty of this method, however, lies in a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 0 °C and 50 °C through a switching method which compensates for the crystal's natural temperature characteristics. This allows for the compensation of any influences on the crystal such as the compensation of the non-linear temperature characteristics and the ageing of both the crystal and other oscillating circuit elements, as well as the reduction of the output frequency measurement errors with the help of an additional reference frequency. The experimental results show that the switching method greatly improves the measurement of small inductance changes in the range between μH and nH, allowing as a result high-precision measurements (~0.35 fH) in this range.

No MeSH data available.