Antenne Double V inversé RHCP & LHCP par Jean-Claude DUCASSE

DOCUMENTATION F1QM

NVIS Field Research in Spain
Science or Adventure?
dr. ing. B. A. Witvliet [wit fleet]
PE5B, MØIJQ

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

HamSCI meeting
NJIT, Newark, NJ, USA
23-24 February 2018

DOCUMENTATION F1QM

1

Introduction
Ben Witvliet [wit fleet]
Born in 1961 in Netherlands New Guinea
Father JZoCW, brother OZ1KGU, uncle PAoWDW
1973
1981
1982
1989
1993
1996
2016
2017

NL4496 (SWL)
PA3BXC
3A/PA3BXC
4X/PA3BXC
5R8DS
PA5BW
PE5B
MØIJQ

My first receiver

Otra 9R-4J vacuum tube receiver with BFO

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

2

Introduction
Ben Witvliet [wit fleet]
I have made my passion my work
Telecom industry

Applied research

Trans World Radio –
Monte-Carlo, Monaco
KPN Telecom –
The Netherlands

f1qm@orange.fr

Radiocommunications
Agency Netherlands

Academic research

Radio Netherlands –
Madagascar

University of Twente
The Netherlands

Netherlands
Broadcasting Company

University of Bath
United Kingdom

https://www.qrz.com/db/F1QM

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3

The story
I will tell you the story of curiosity-driven research
into the role of radio wave polarization
in short-distance HF communication (NVIS).
Hidden messages:
 Prepare well, and you will find amazing things!
 Science is adventure!

f1qm@orange.fr

https://www.qrz.com/db/F1QM

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4

Just an ordinary day at the office (2008)
Radiocommunications Agency Netherlands
Monitoring station

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

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5

But then it happened …
PAØSIM:
“I receive local stations on 3.5 MHz with
Right-Hand Circular Polarization,
and Jugoslav stations with
Left-Hand Circular Polarization, and ... ”
We: “You … what !?”

?
real / not real

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

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6

But then it happened …
We decided to visit him. And we stayed very late..!!
2x Alford loop

2x modified FT1000MP

http://www.pa0sim.nl/
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

7

This is where the journey starts …

amplitude

We re-discovered the work of Appleton (1933) …

time

ground wave
circularly polarized, with clockwise rotation (RHCP)
circularly polarized, with counter-clockwise (LHCP)

Appleton, E. V., and G. Builder (1933), "The Ionosphere as a Doubly-Refracting Medium,“
Proc. Phys. Soc., 45, (2), pp. 208-220.
f1qm@orange.fr

https://www.qrz.com/db/F1QM

0:03

DOCUMENTATION F1QM

8

This is where the journey starts …
… and combined it with ionospheric simulations
Two paths with different delay
and attenuation (varying)

Ordinary wave
Extraordinary wave

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

9

This is where the journey starts …
We followed the changing propagation over the day
9 March 2014
Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

No reception
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

10

This is where the journey starts …
We followed the changing propagation over the day
9 March 2014
sunrise
Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

RHCP
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

11

This is where the journey starts …
We followed the changing propagation over the day
9 March 2014
Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

Polarisation fading
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

12

This is where the journey starts …
We followed the changing propagation over the day
9 March 2014
Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

Polarisation fading
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

13

This is where the journey starts …
We followed the changing propagation over the day
9 March 2014
Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

Polarisation fading
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

14

This is where the journey starts …
We followed the changing propagation over the day
9 March 2014
after
sunset

Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

Polarisation fading
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

15

This is where the journey starts …
We followed the changing propagation over the day
9 March 2014
Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

RHCP
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

16

This is where the journey starts …

0:05

We followed the changing propagation over the day
9 March 2014
Ray-tracing simulations
The Netherlands
7 MHz, SSN 79

Ordinary wave
Extraordinary wave

No reception
Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

17

This is where the journey starts …
… and divined the location of the Pot of Gold

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

18

This is where the journey starts …
… and divined the location of the Pot of Gold
“band open”
“Happy Hour”
RHCP reception
(Northern hemisphere)

“band
closed”

“band
closed”

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

19

This is where the journey starts …
This led to a curiosity-driven experiment …

If we transmit in linear polarization,
will we see RHCP
during “Happy Hour” ?

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

20

A very adventurous journey (first leg)
This led to a curiosity-driven experiment …
ionosphere
RHCP

LHCP
Turnstile
Antenna

PA

Phasing

TX

RX

Witvliet, Ben A., et al. "The importance of circular polarization for diversity reception and MIMO in NVIS
propagation." Antennas and Propagation (EuCAP), 2014 8th European Conference on. IEEE, 2014.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

21

A very adventurous journey (first leg)
… using equipment that was “just lying around” 
5.39 MHz Turnstile Antenna

Rohde & Schwarz FSMR26
$100,000

Witvliet, Ben A., et al. "The importance of circular polarization for diversity reception and MIMO in NVIS
propagation." Antennas and Propagation (EuCAP), 2014 8th European Conference on. IEEE, 2014.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

22

A very adventurous journey (first leg)
… using equipment that was “just lying around” 

Improvised phasing network
Δφ = +90º or -90º
(switched)
Δφ=0º
∑
Δφ=90º

Δφ=180º
Witvliet, Ben A., et al. "The importance of circular polarization for diversity reception and MIMO in NVIS
propagation." Antennas and Propagation (EuCAP), 2014 8th European Conference on. IEEE, 2014.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

23

A very adventurous journey (first leg)
… using equipment that was “just lying around” 
Scrap-heap challenge
PAØA transmitter on 5.39 MHz
P = 800 Watts, ΔP < 0.1 dB
f = 5.39 MHz, Δf < 5 Hz
1 minute on / 1 minute off
DCF controlled timing
Witvliet, Ben A., et al. "The importance of circular polarization for diversity reception and MIMO in NVIS
propagation." Antennas and Propagation (EuCAP), 2014 8th European Conference on. IEEE, 2014.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

24

Results of the first leg
First “Happy Hour” observations!

LHCP radio signal
RHCP radio signal

70
60
Signal strength [dBuV] →

50
40

13 dB
characteristic
wave isolation

30
20

LHCP radio noise
RHCP radio noise

10
0
-10
09:30

10:30

11:30

12:30

13:30

Witvliet, Ben A., et al. "The importance of circular polarization for diversity reception and MIMO in NVIS
propagation." Antennas and Propagation (EuCAP), 2014 8th European Conference on. IEEE, 2014.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

25

Results of the first leg
Arrived at the horizon, a new one that beckons …

If we improve our turnstile antenna,
will we observe more
characteristic wave isolation ?

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

26

A very adventurous journey (second leg)
So we made our Turnstile antenna very symmetrical

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

27

A very adventurous journey (second leg)
… perfected the phasing network …
Δφ = 0.1º, ΔP < 0.05 dB

Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

28

A very adventurous journey (second leg)
… and increased the measurement speed 30x

FlexRadio

f1qm@orange.fr

R&S FSMR

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

29

Results of the second leg
Now we see 25 dB characteristic wave isolation!

---- ordinary
---- extraordinary
Happy Hour

25 dB

---- difference
sunset

sunrise
Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

30

Results of the second leg

0:10

Now we see 25 dB characteristic wave isolation!

25 dB

Happy Hour

Happy Hour

sunset

sunrise
Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

31

Results of the second leg
Now we see 25 dB characteristic wave isolation!

25 dB

Happy Hour

Happy Hour

Witvliet, Ben A., et al. "Measuring the Isolation of the Circularly Polarized Characteristic Waves in NVIS
Propagation [Measurements Corner]." IEEE Antennas and Propagation Magazine 57.3 (2015): 120-145.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

33

Results of the second leg
All our measurements were on 1 path at 53˚ North.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

32

Results of the second leg
So that made us wonder:

Can we confirm these results at a
different latitude, other distances
and azimuths?

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

34

A very adventurous journey (third leg)
What if we’d change latitude … ?

Earth’s magnetic field
tilt angle
The Netherlands

Barcelona, Spain
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

35

A very adventurous journey (third leg)
… and measure 6 paths simultaneously?

Tx1

Tx4
https://www.qrz.com/db/F1QM

Tx6

Tx5

Tx4

Frequency 

Tx3
f1qm@orange.fr

Tx3

Power 

Rx

Tx2

1 kHz
Tx1

Tx2

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36

A very adventurous journey (third leg)
… and measure 6 paths simultaneously?

Cooperation with
LaSalle University
of Barcelona, Spain

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

37

A very adventurous journey (third leg)
… and measure 6 paths simultaneously?
2 synchronous
antenna inputs

Apache Labs
ANAN-200D receiver

6000 (x2)
meas/sec

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

38

A very adventurous journey (third leg)
No more scrap-heap challenge transmitters!

2 Watts

Automated transmit sequence

Witvliet, Ben A., et al., "A transportable hybrid antenna-transmitter system for the generation of elliptically polarized
waves for NVIS propagation research]," European Conference on Antennas and Propagation, Davos, 2016.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

39

A very adventurous journey (third leg)
No more scrap-heap challenge transmitters!
Wire antenna elements
and baluns
Beacon transmitter
Mast 6.3 m
Mastfoot
Battery
Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

40

A very adventurous journey (third leg)
No more scrap-heap challenge transmitters!
transmitter

battery

Witvliet, Ben A., et al., "A transportable hybrid antenna-transmitter system for the generation of elliptically polarized
waves for NVIS propagation research]," European Conference on Antennas and Propagation, Davos, 2016.

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

41

A very adventurous journey (third leg)
12 months later, time to hit the road!
8
16
8
2
10
32
2
(3
Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

antenna masts
dipole antennas
beacon transmitters
meas. receivers
batteries
guy wires
tool sets
researchers)

DOCUMENTATION F1QM

42

A very adventurous journey (third leg)
12 months later, time to hit the road!

Travel to Spain

1800 km

Visit University Barça

200 km

Installing beacons

900 km

Retrieving beacons

900 km

Travel back

1800 km +

Total

5600 km
(3,500 mls)

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

43

A very adventurous journey (third leg)
Interesting field work!
Beacon 1

We’re in
sheep shit!

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

44

A very adventurous journey (third leg)
Interesting field work!
Beacon 5

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

45

A very adventurous journey (third leg)
Interesting field work!

On Holy Ground
(by mistake)

Receiver

f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

47

Results of the third leg
And interesting results!
2 Watt beacons

50 dB
SNR

Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

48

Results of the third leg

0:17

And interesting results!
Rx input 2

Beacon 6
Beacon 5
Beacon 4

Beacon 3
Beacon 2
Beacon 1
Time [CET] →
Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

DOCUMENTATION F1QM

48

Results of the third leg
And interesting results!

EA 3 R K L

Rx input 2

Time [CET] →
Radiocommunications
Agency Netherlands
f1qm@orange.fr

https://www.qrz.com/db/F1QM

-

6

DOCUMENTATION F1QM

49

Results of the third leg
Morning Happy Hour, beacon 1

Tx
Happy Hour reception in linear polarization

Isolation
>20 dB!
Radiocommunications
Agency Netherlands
f1qm@orange.fr

Time →
https://www.qrz.com/db/F1QM