Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.cplire.ru/html/lab234/pubs/2008_08a.pdf Дата изменения: Mon Jan 19 22:35:18 2009 Дата индексирования: Tue Oct 2 09:18:11 2012 Кодировка: Поисковые слова: m 97

Phase-locked Local Oscillator for Superconducting Integrated Receiver
Valery Koshelets, Andrey Ermakov, Pavel Dmitriev, Lyudmila Filippenko, Andrey Khudchenko, Nickolay Kinev, Oleg Kiselev, Alexander Sobolev, and Mikhail Torgashin
Institute of Radio Engineering and Electronics (IREE), Moscow, Russia
The work was supported by the RFBR projects 06-02-17206, ISTC project # 3174, NATO SfP Grant 981415, and the President Grant for Scientific School 5408.2008.2

April 29, 2008; Groningen

19th International Symposium on Space Terahertz Technology

1


Phase-locked Local Oscillator for Superconducting Integrated Receiver
Outline
· · · · · · · Superconducting Integrated Receiver (SIR) Flux Flow Oscillator (FFO) for the TErahertz LImb Sounder (TELIS) project NbN FFO for TELIS ­ new features: continuous frequency and power tuning; FFO linewidth Remote optimization of the FFO/SIR operation PL FFO phase noise & spectral ratio New approaches and future FFO applications Conclusion
April 29, 2008; Groningen 19th International Symposium on Space Terahertz Technology 2


Internal part of the SIR Microcircuit
Double-slot (dipole) twin SIS ­ 0.8 µm2

FFO 400*16 µm

2

HM ­ 1.0 µm

2

Nb-AlOx-Nb or Nb-AlN-NbN;

Jc = 5 - 10 kA/cm

2 2

Optionally: SIS ­ Jc = 8 kA/cm2; FFO + HM = 4 kA/cm
Wednesday , April 30, 11.05; SIR for TELIS Report 10-2 by Pavel Yagoubov

3


Superconducting Integrated Receiver for

TELIS - TErahertz LImb Sounder

Wednesday , April 30, 11.05; SIR for TELIS Report 10-2 by Pavel Yagoubov

4


Flux Flow Oscillator based on Long Josephson Junction
Bias current IB

Control line current ICL

Radiation

5


Quality of the AlOx and AlN tunnel barriers on the current density
Rn*S, *µ
200 40 35 30 25 Rj/Rn 20 15 10 5 0 1 10 Jc, kA/cm
2

2

20

2

Nb-AlOx-Nb Nb-AlN-Nb Nb-AlN-NbN

100
6


Nb-AlN-NbN FFO for SIR; new features
400 GHz

700 GHz

JSC, VB = Vg/3

V.P. Koshelets, et al, Phys. Rev. B, vol. 56, pp 5572-5577, (1997)

7


Nb-AlN-NbN SIS pumped by FFO; FFO frequency tuning
HD13-09#26 (Vg=3.7mV, Rn=21 Ohm)
300 250

SIS Current (mkA)

200 150 100 50 0
FFO Frequency: 0 GHz 400 GHz 500 GHz 600 GHz 700 GHz

0

1

2

3

4

5

6

7

SIS Voltage (mV)
8


Nb-AlN-NbN SIS pumped by FFO; FFO power tuning (f = 500 GHz)

9


FFO Spectrum

-10 -15 -20 FFO Power (dBm) -25 -30 -35 -40 -45 -50 431,56 431,58 431,60 431,62 431,64
10
Experimental Data Symmeterizated Data Lorentzian Gaussian

FFO Frequency (GHz)


Frequency dependence of the FFO: Nb-AlOx-Nb and Nb-AlN-NbN circuits

20

FFO Linewidth (MHz)

15

Nb-AlN-NbN Nb-AlOx-Nb

10

5

0 350

400

450

500

550

600

650

700
11

750

FFO Frequency (GHz)


SIR for TELIS ­ remote operation on the Fiske steps

FFO frequency of about 500 GHz
12 10

FFO linewidth, Hz

8 6 4 2 0

1,030

1,032

1,034

1,036

1,038

FFO voltage, mV

Cryogenic Phase Locking Loop System for Flux-Flow Oscillator Poster P6-7 by Andrey Ermakov

12


SIR for TELIS ­ remote operation: QP vs Josephson

13


Frequency and Phase Locked spectra of the Nb-AlN-NbN FFO
-20 -25 IF Output Power (dBm) -30 -35 -40 -45 -50 -55 -60 360 380 400 420 440
Power (dBm)
0

Phase locked at 605 GHz (SR = 92 %) Frequency locked Linewidth = 1.7 MHz

Span - 100 MHz Resolution Bandwidth - 1 MHz

-20

Spectrum analyzer Resolution Banwidth RBW = 1 Hz

-40

-60

Down-converted FFO Frequency (MHz)

-80

-100 -50

-40

-30

-20

-10

0

10

20

30

40

50

Offset from carrier (Hz)

14


Phase Noise of the PL FFO
Absolute FFO phase noise, (n = 20); SR = 96.7% 2 R&S Synthesizer at 22 GHz * n (n = 20) Phase locked FFO, fFFO = 450 GHz (faut = 0.5 MHz; SR = 97.7%)) R&S Synthesizer at 22 GHz (Specification)

-30 -50 Phase Noise (dBc/Hz) -70 -90 -110 -130 -150 10 100 1k 10k 100k 1M 10M
15

Offset from Carrier (Hz)


PL FFO Phase Noise and Spectral Ratio
300
RMS Phase Noise (), fs

250 200 150 100 50 0 50
LO = 600 GHz

Spectral Ratio (% of the PL FFO Power)

100

80

T

=

1



60

LO

1 - SR SR

40
Spectral Ratio (% of the PL FFO Power) 100

60 70 80 90 Spectral Ratio, %

100

20

Experim ental D ata; TELIS PL L JAP, 102, 063912 (2007) R egulation B W = 10 M H z

80

0

1

10

60

Free -r unning FFO Linew idth (M H z )

40
FFO Linew idth 1 MHz 3 MHz 10 MH z

20

0

10 PLL Regulation Bandw idth (M Hz)

10 0

16


Linewidth of free-running FFOs and SR for the PL FFO as a function of FFO width (RnS =30 *µm2)
30 25 FFO Linewidth (MHz) 20 15 10 5 0
, , , fFFO = 526 GHz fFFO = 616 GHz fFFO = 706 GHz

90 75 60 45 30 15 0 10 12 14 16 18 20 22 24 26 28 30 Spectral Ratio of the PLL FFO (%)
17

4

6

8

FFO Width, W (µm)


Suppression of the FFO voltage noise
The FFO voltage is independently controlled by the two currents IB and ICL noisy! noiseless Correlated convey of the FFO bias current noise into the magnetic field (ICL)

Relation between the amplitude of the FFO noise current and voltage noise

A sh X 2 ( ) Vnoise( ) = Rd X 1 ( ) - Rd A1 + 2

CL

Inoise
18


Cryogenic PLL System
-20 -25 -30

Free running FFO; LW = 2 MHz Cryo PLL; SR =91 % Regular RT PLL; SR =82 % For the FFO LW = 10 MHz CryoPLL provides SR = 50 %, while the RT PLL gives only 20 %
Spectral Ratio (% of the PL FFO Power) 100

IF Power, dBm

-35 -40 -45 -50 -55 -60 -65 350 370 390 410

80

60

40
FFO Linew idth 1 MHz 3 MHz 10 MHz

20

0

430

450

10 PLL Regulation Bandw idth (M Hz)

100

Down-Converted FFO Frequency, MHz

Cryogenic Phase Locking Loop System for Flux-Flow Oscillator Poster P7-7 by Andrey Khudchenko

19


SIR Resolution & Stability
Gas cell measurements; resolution determined by DAC
210 200 190 180 170 160
dA
2

IF amp SIS

Power meter BP filter

FFO
OCS gas, P=2mB
1E-4

Allan variance test
Phase-locked SIR

1E-5

T, K

150 140 130 120 6100 6120 6140 6160 6180 6200 6220 6240 6260 6280

1E-6

1E-7

IF frequency, MHz

0.01

0.1

1

10

100

t, sec

Wednesday , April 30, 11.05; SIR for TELIS Report 10-2 by Pavel Yagoubov

20


Conclusion
· · · Concept of the Phase-locked SIR is developed and tested. Nb-AlN-NbN FFOs and SIRs have been successfully implemented. Improved design of the FFO for TELIS has been developed and optimized; free-running linewidth from 0.5 to 10 MHz recorded in the frequency range 350 ­ 740 GHz that allows to phase lock from 35 up to 97 % of the FFO power. 3-rd generation of the SIR with PL FFO for TELIS has been developed showing a possibility to realize TELIS requirements: Frequency range 500 ­ 650 ; Noise Temperature < 150 ; IF bandwidth 4 - 8 ; Spectral resolution better 1 . Procedure for remote optimization of the PL SIR operation has been developed and experimentally proven. First TELIS flight is scheduled on May - June, 2008 (Terezina, Brazil). Approaches to increase SR of the PL FFO proposed and tested. Future space missions are under consideration.
21

·

· · · ·