Wide-Range Tuner for Generators in THz Bands

Alexander Denisov

1.2

, Jinghui Qiu

, Shengchang Lan

, Ming He

, Yang Xiong

, Fan Zhang

Han Zhang

and Francesco Soldovieri

State Research Center “Iceberg”, Kiev, Ukraine

Department of Microwave Engineering, Harbin Institute of Technology, P.R.China

College of Electronic Information and Optical Engineering, Nankai University, Tianjin300071, P.R.China

Istituto per il Rilevamento Elettromagnetico dell'AmbienteConsiglio Nazionale delle Recerche ,Napoli, Italy

alex_denisov2009@ukr.net, qiujh@hit.edu.cn, heming@nankai.edu.cn, soldovieri.f@irea.cnr

Keywords: Josephson junction, unknown power, frequency measuring, sensitivity, electromagnetic radiation, terahertz

band.

Abstract: Before experiments can be conducted on new generation structures in the THz band when the level of

power is small and especially the frequency are practically unknown correctly ( or it has place some

accidental character) it is necessary to have instruments capable of measuring weak signals in a wide-range

frequency band. Receiving instruments for the above-described evaluations must be based better by one

measuring block and not only in the limits of the intermediate frequency (IF) amplifier band. Best natural

“candidate” for this task is Josephson junction (JJ) – it has super wide voltage electronic regulation on

frequency by basic ratio 2eV= hω. JJ can be used as the criterion for a single-block super-wide band

frequency-meter and as a sensitive element for the tuning the generation structures. Short description

presents the realized innovative idea about simple tuner for generators in THz bands.

1 INTRODUCTION

The idea for this work came after visiting several

labs which had interest to realize electromagnetic

radiation (EMR) using Josephson media (JM) (H. B.

Wang, S. Guénon, etc., 2010) and practical requests

for possible good but cheap receivers covering the

short part of millimeter band with enough wide

bandwidth of the intermediate frequency (IF)

amplifier. These labs worked only with liquid

nitrogen and oriented on the structures based on high

temperature superconductor (HTSC) such as

CaCu

8 + δ

(A. Koshelev and L. Bulaevskii.,

2008, K. Kadowaki, L. Ozyuzer etc, 2008, D.

Crankshaw, Enrique Trias., 2001).

Finally, it is worth to mention that purchasing a

reliable enough cryocooler based on closed Giffard-

McMagon (GM) cycle working till the temperature

of a liquid helium is not a big issue today

(www.fullsharecryogenics.com).

At least the price of GM machine is not

principally more than famous network analyzer

“Agilent”. If to talk about the perspective using for

the above task the Josephson junctions in spite that it

is necessary to use cooling from the point of possible

alternative to “Agilent” or some the same - from the

“the rules of contraries”- there absent other good

alternative.

The primary trend in superconductive microwave

radio-electronics is the using JJ through the

development of the devices employing Josephson

oscillation, based on non-stationary Josephson-effect

(K. Likharev, B. Ul’rich -1978, I. Kulik, I. Yanson,

1972). This can be used for the development

principally new devices which are difficult or

impossible to realize by the other methods.

Denisov A., Qiu J., Lan S., He M., Xiong Y., Zhang F., Zhang H. and Soldovieri F.

Wide-Range Tuner for Generators in THz Bands.

DOI: 10.5220/0005889100390042

In Proceedings of the Fourth International Conference on Telecommunications and Remote Sensing (ICTRS 2015), pages 39-42

ISBN: 978-989-758-152-6

On the basis of the previous theoretical and

experimental investigation (A.Denisov, V.

Obolonsky, 1990, A.Denisov, V.Gorishnyak, 1981,

A. Denisov, V.Gaevsky., 1985) there shortly described

the innovation decision about wide-range tuner for

generators in THz bands.

Why tuner? What is necessary for the tuning of

generator? It is need some visual control about

frequency and the power of EMR. In reality the

calculation of new generation structure can be done

according to some current theoretical model and

naturally in the simplest approximation. According

to this and the real possible mistakes the frequency

of EMR has some accident character, so the receiver

with standard mixer even with big band of the

intermediate frequency is not enough for this task.

In the practical case at the beginning of the

experiments the generation power is small enough

too. Real situation. Besides of this the microwave

losses in the transmission line can be very big too

according to practically full absence the devices for

such control and the matching in THz band.

There raised the question - where is the best

suitable decision?

For such task it is need the tuning device with

super wide band and with best sensitivity. In this

case it will be real guarantee we would not “sleep

past cash-box”.

This is proved by two devices based on the JJ.

First one is the sensitive receiver based on self-pump

mode regime of JJ and second one is the using JJ as

the criterion according to 2eV = hω (for the

frequency measurement by the super wide

frequency-meter. Combination of this two devices in

one single block was published before) (A.Denisov,

Qiu Jing Hui, 2014, A. Denisov, A.Gudkov, 2015)

Perhaps, it’s interesting to say the fact ( A.

Denisov , A.Gudkov., 2015) that in 1978 it was the

first S&R works to create the practical devices of the

generators based on Impatt structures in Scientific

Research Institute “Saturn” in Kiev, was oriented on

R&D of low and super low noise microwave

receivers in former USSR. It was practically lack of

measuring devices in frequency bands more than

100 GHz. Spectrum analyzer C4-28 works till~38,5

GHz, and the existing certificated frequency-meter

and power-meter worked practically till the same

limiting frequency. It was realized the first variant of

the panoramic sweep generator with monitor for

measuring Standing Wave Ratio (VSWR) had been

working in 3 mm. It was a real task to construct the

generator of 70 GHz. It was came up with the idea to

use ‘Shapiro steps” (K.Likharev, B.Ul’rich -1978) –

their level and position along voltage-frequency

scale for the tuning and matching the “room-

temperature” Impatt generator to the biggest power.

Experiments were successful, but not only for 70

GHz. we elaborated the second harmonic and tuned

the Impatt generator on 140 GHz. However, since

the certificated measuring equipments were lucking,

it was really difficult to confirm the obtained results

and to convince the corresponding technical

standard control personnel. We observed the

harmonics of 140 GHz till more than 1,5 THz with

the help of our first analogue variant of the

Josephson frequency-meter (A.Denisov,

V.Obolonsky, 1990) built on Nb point contact had

been working according to the “Shapiro steps” on

Current-Voltage Characteristic (IVCh) of the JJ

(patented in USSR in 1978).

First of all, this device had extremely super wide

momentary wave band. It was not necessary to

change the measuring block to modify the measuring

frequency band.

2 TECHNICAL EXPLANATION

On fig.1 and fig, 2 presented typical Volt-Amper

Characteristic (VACh) of the JJ. Result on fig.1 was

made from Tl based HTSC film by one of the author

of this work. EMR of the experimental generator

falls on JJ which produces microwave radiation

according to 2eV= hω and later visual control of the

Shapiro steps on VACh can be used for the tuning

and matching of the experimental generator. To

obtain a quantitative measure of the microwave

power sensed by the Josephson junction, the well

known dependence of the Shapiro step width on

incident microwave power can be employed.

In term of Josephson-effect theory, the reduction

of zeroth Shapiro step width is equivalent in quantity

to diminish the critical current I

of JJ which depends

on EMR power as zeroth Bessel function. This

current which is the result of interference of two

signals on JJ has direct influence on the width of the

steps. So, the width of the steps or



I on Fig 1 is the

measure of EMR falling on JJ.

And naturally the position of Shapiro steps on

the voltage scale of VACh corresponds to the

frequency which falls on JJ.

Fourth International Conference on Telecommunications and Remote Sensing

Figure 1: Typical VACh of Josephson junction.

Figure 2: Typical picture of JJ with Shapiro steps

Figure 3: Explanation of how Shapiro steps

measurements’s JJ frequency meter is operating.

If to transform typical picture of the Shapiro

steps on Fig.2 from co-ordinate I-V to co-ordinate

V-I and to use transformer in bias network (there is

the linear voltage shifting law, where dV/dt ~ fixed

constant) it will be situation as on fig.3.

According to Shapiro steps there arise impulses

from the second winding. These impulses are given

directly by:

ω = (2e|dV/dt | • ∆ t) h

(1)

The interval between impulses from the second

(step-up) winding of the transformer bring needed

information about frequency of EMR and after

calibration can be re-calculated into the automatic

scheme for the frequency measuring.

This time it is reason to remember the result with

Tl -based HTSC on fig.1. Based on the Josephson -

effect the intrinsic abilities the gap frequency of

HTSC is about 30 THz (P. Wang, Zh. Wang, B. Fan,

W. Xie, X. J. Zhao, M. He, X. Zhang, L. Ji, and S. L.

Yan., 2012), which is higher than that of low

temperature superconductor.

It denotes that the wide-range THz tuner which is

combination of simplest visual power meter and

frequency meter based on the Shapiro steps

properties in the single block can respond at all the

THz band.

3 CONCLUSION

In this paper it was done simplest explanation how

to use Shapiro steps which have place in case EMR

of JJ for the wide-range tuning of experimental

generator in THz band.

It will be especially popular for the tuning of

cooled generator.

As the real prognosis - possible later such device

will take name Shapiro-steps tuner of generators in

THz band.

ACKNOWLEDGEMENTS

This work was prepared according to the finance

support by national program of the People’s

Republic of China “The Recruitment Program of

Foreign Experts” under the State Administration of

Foreign Experts Affairs.

REFERENCES

Wang H.B., Guénon S., Gross B., Yuan J., Jiang Z. G.,

Zhong Y.Y., Grünzweig M., Iishi A., Wu H., Hatano

T., Koelle D., Kleiner R.., 2010. “Coherent Terahertz

Emission of Intrinsic Josephson Junction Stacks in the

Hot Spot Regime“,Phys. Rev. Lett. 105, 2010.

Koshelev A.E., Bulaevskii L.N. 2008. “Resonant

Electromagnetic emission from intrinsic Josephson -

junction stacks with laterally modulated Josephson

critical current” Phys. Rev. B 77, 014530,2008.

Wide-Range Tuner for Generators in Thz Bands

Kadowaki K., Ozyuzer L., Koshelev A., Kurter C., Gray

K.., 2008 “Direct observation of Terahetz

Electromagnetic waves emitted from intrinsic

Josephson junctions in single crystalline Bi-ceramics”,

Physica C, vol.468, p. 634, 2008.

Crankshaw D. S., Trias E., and Orlando T.P. 2001,

Magnetic Flux Controlled Josephson Array

Oscillators. IEEE Trans. On Appled

Superconductivity, Vol. I I , No. I, March 2001, I223

ww w.fullsharecryogenics.com

Likharev K., Ul’rich B.., 1978. “Systems with Josephson

contacts”, MGU Press, Moscow, 1978. I.Kulik, I.

Yanson., 1972. Josephson-effect in Superconducting

Tunneling Structures, Halsted press, 1972.

Denisov A. Obolonsky V., 1990. “Frequency measurement

in millimeter in submillimeter electromagnetic wave

bands using Josephson junctions” Second World

Congress on Superconductivity, Houston, Texas,USA,

10-15, 1990.

Denisov A., Gorishnyak V., 1981 “Digital frequency

meter based on Josephson Junctions”, Soviet

“Electronika of microwaves, TsNII “Electronika”,

vol.4, 1981, p. 45-55, 1983. [

Denisov A., Gaevsky V., Gassanov L., Kuzenkov S.,

Nazarenko L., 1985. “Study of the operation of

Josephson Down-Converter in the Self Pump Mode”,

Soviet “Radiotechnika i elektronika”, №.5, p.1006,

1985.

Denisov A., Qi J., Hui Q. J., Gudkov A..,2015 Possibilities

to make the panoramic receiver- frequencymeter in

terahertz band based on Josephson junctions, IEEE

Trans. On Appl. Superconductivity, Vol. 25, No. 2,

April20151800909.

A.Denisov, Hui Q. J., Qi J., Chen L.. 2014 Towards to

make universal device for doing experiments with new

generation structures in terahertz band. 20

International conference on microwaves, Radar and

Wireless Communication, MIKON –2014, Gdansk,

June 16-18, 2014

Wang P., Wang Zh., Fan B., Xie W., Zhao X. J., He M.,

Zhang X., Ji L., and Yan S. L.., 2012. Millimeter-

Wave Radiation from Misaligned Tl2Ba2

CaCu2O8Thin-Film Intrinsic Josephson Junctions.

IEEE Trans. on Applied Superconductivity, Vol. 22,

No. 5, October 2012: 1500503

Fourth International Conference on Telecommunications and Remote Sensing