Rainee N. Simons and Edwin G. Wintucky

Glenn Research Center, Cleveland, Ohio

Multi-Tone Millimeter-Wave Frequency Synthesizer 

for Atmospheric Propagation Studies

NASA/TM—2014-218122

April 2014
NASA STI Program . . . in Profi le

Since its founding, NASA has been dedicated to the 

advancement of aeronautics and space science. The 

NASA Scientifi c and Technical Information (STI) 

program plays a key part in helping NASA maintain 

this important role.

The NASA STI Program operates under the auspices 

of the Agency Chief Information Offi cer. It collects, 

organizes, provides for archiving, and disseminates 

NASA’s STI. The NASA STI program provides access 

to the NASA Aeronautics and Space Database and 

its public interface, the NASA Technical Reports 

Server, thus providing one of the largest collections 

of aeronautical and space science STI in the world. 

Results are published in both non-NASA channels 

and by NASA in the NASA STI Report Series, which 

includes the following report types:

• TECHNICAL PUBLICATION. Reports of 

completed research or a major signifi cant phase 

of research that present the results of NASA 

programs and include extensive data or theoretical 

analysis. Includes compilations of signifi cant 

scientifi c and technical data and information 

deemed to be of continuing reference value. 

NASA counterpart of peer-reviewed formal 

professional papers but has less stringent 

limitations on manuscript length and extent of 

graphic presentations.

• TECHNICAL MEMORANDUM. Scientifi c 

and technical fi ndings that are preliminary or 

of specialized interest, e.g., quick release 

reports, working papers, and bibliographies that 

contain minimal annotation. Does not contain 

extensive analysis.

• CONTRACTOR REPORT. Scientifi c and 

technical fi ndings by NASA-sponsored 

contractors and grantees.

• CONFERENCE PUBLICATION. Collected 

papers from scientifi c and technical 

conferences, symposia, seminars, or other 

meetings sponsored or cosponsored by NASA.

• SPECIAL PUBLICATION. Scientifi c, 

technical, or historical information from 

NASA programs, projects, and missions, often 

concerned with subjects having substantial 

public interest.

• TECHNICAL TRANSLATION. Englishlanguage translations of foreign scientifi c and 

technical material pertinent to NASA’s mission.

Specialized services also include creating custom 

thesauri, building customized databases, organizing 

and publishing research results.

For more information about the NASA STI 

program, see the following:

• Access the NASA STI program home page at 

http://www.sti.nasa.gov

• E-mail your question to help@sti.nasa.gov

• Fax your question to the NASA STI 

Information Desk at 443–757–5803

• Phone the NASA STI Information Desk at

 443–757–5802

• Write to:

 STI Information Desk

 NASA Center for AeroSpace Information

 7115 Standard Drive

 Hanover, MD 21076–1320
Rainee N. Simons and Edwin G. Wintucky

Glenn Research Center, Cleveland, Ohio

Multi-Tone Millimeter-Wave Frequency Synthesizer 

for Atmospheric Propagation Studies

NASA/TM—2014-218122

April 2014

National Aeronautics and

Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Prepared for the

International Symposium on Antennas and Propagation and USNC/URSI National Radio Science Meeting

sponsored by the Institute of Electrical and Electronics Engineers

Memphis, Tennessee, July 6–12, 2014
Acknowledgments

The support from the 2013 NASA GRC Center Innovation Fund (CIF) is gratefully acknowledged.

Available from

NASA Center for Aerospace Information

7115 Standard Drive

Hanover, MD 21076–1320

National Technical Information Service

5301 Shawnee Road

Alexandria, VA 22312

Available electronically at http://www.sti.nasa.gov

Level of Review: This material has been technically reviewed by technical management. 

This report contains preliminary fi ndings, 

subject to revision as analysis proceeds.
NASA/TM—2014-218122 1 

Multi-Tone Millimeter-Wave Frequency Synthesizer for 

Atmospheric Propagation Studies 

Rainee N. Simons and Edwin G. Wintucky 

National Aeronautics and Space Administration 

Glenn Research Center 

Cleveland, Ohio 44135 

Abstract 

This paper presents the design and test results of a 

multi-tone millimeter-wave frequency synthesizer, based on a 

solid-state frequency comb generator. The intended 

application of the synthesizer is in a space-borne transmitter 

for radio wave atmospheric studies at Q-band (37 to 43 GHz). 

These studies would enable the design of robust high data rate 

space-to-ground satellite communication links. 

1.0 Introduction 

The frequency spectrum allocated and utilized currently for 

satellite communications uplinks and downlinks are rapidly 

getting congested due to very heavy usage. The logical choice 

is to move higher up in frequency into the millimeter-wave 

(mm-wave) frequency bands, which are sparsely used. The 

mm-wave bands include frequencies in the Q-band (37 to 

42 GHz) and the V/W-band (71 to 76 GHz). Migrating to the 

mm-wave frequency bands has the added advantages of 

smaller antenna size and lower mass for a given spacecraft 

effective isotropic radiated power (EIRP). In addition, in the 

case of commercial communications satellites, which use 

multiple beams to increase throughput, the beamwidth for a 

given antenna aperture size is smaller at the above mm-wave 

frequencies. The smaller beamwidth results in a smaller spot 

size on ground, which allows packing greater number of spot 

beams over a given area and thus enables greater spectral 

efficiency through frequency reuse. Prior to system planning 

and system design for deployment in space, it is essential to 

investigate the effects of Earth’s atmosphere on radio wave 

propagation at the above frequencies. In general, radio waves 

suffer increasing attenuation, scintillation, depolarization, and 

group delay due to atmospheric gases, clouds and rain (Ref. 1). 

In this paper, we present the design, construction and test 

results for a multi-tone frequency synthesizer (Ref. 2) based 

on the discrete frequency spectrum produced by a high 

frequency solid-state comb generator. Unlike the single 

frequency beacon source, which flew on NASA’s Advanced 

Communications Technology Satellite (ACTS) (Ref. 3) for 

Ka-band propagation experiments (Ref. 4), the multi-tone 

frequency synthesizer is capable of simultaneously delivering 

coherent multiple frequencies. These multiple frequencies 

enable characterizing the frequency dependent group delay 

effects, which are essential for the design of high data rate 

wide band satellite communications links. 

2.0 Multi-Tone Frequency Synthesizer 

Architecture 

2.1 Multi-Tone Frequency Synthesizer 

Circuit Design, Construction and 

Mode of Operation 

A simplified block schematic of the basic multi-tone 

frequency synthesizer based beacon transmitter that could fly 

on a geostationary satellite as a hosted payload for radio wave 

propagation experiments at mm-wave frequencies is presented 

in Figure 1. The synthesizer consists of a comb generator, 

which puts out evenly spaced harmonic frequencies of the 

input signal, which are coherent and tunable over a wide 

frequency range. These harmonics are then amplified to the 

power level needed for radio wave propagation studies. 

Harmonics that are amplified are simultaneously transmitted 

as beacon signals from space to receiving ground stations 

located at several climate zones within the CONUS. By 

measuring the signal relative strength and phase at ground 

sites one can estimate the attenuation and group delay or 

dispersion due to atmospheric induced effects. 

2.2 Rational for a Multi-Band Multi-Tone 

Frequency Synthesizer Circuit, Design, 

and Construction 

Significant amount of statistical data has been accumulated 

since the pioneering ACTS experiments of the 1990’s and 

accurate models that predict the impairments to radio waves in 

the 20/30 GHz bands due to Earth’s atmosphere are available. 

In addition, communications satellite systems are currently 

operational at these frequencies. It is also well understood that 

signals at Q-band and V/W-band frequencies would 

experience much higher attenuation during rain fades than 

signals in the 20/30 GHz range. The deep fades will result in 

poor signal-to-noise ratio at the Q-band and V/W-band beacon 

receivers on ground, which could cause the receivers to lose 

frequency/phase lock. To overcome this problem it is desirable 

to include a coherent K-band (18 to 26.5 GHz) beacon source 

along with the Q-band and V/W-band beacon sources on the 

payload. Because of higher signal-to-noise ratio at K-band, the 

beacon receiver on ground can retain lock during deep fades 

and thus enable high availability attenuation measurements or 

characterization. This data is valuable and can provide a 
NASA/TM—2014-218122 2 

reference for model development and also provide an 

understanding of frequency model scaling factors for future 

system design when Q-band and V/W-band propagation data 

is unavailable (Ref. 1). 

A block schematic of the multi-band multi-tone frequency 

synthesizer breadboard circuit is presented in Figure 2. The 

synthesizer consists of a high frequency wideband solid-state 

comb generator. The K-band and Q-band harmonics are 

separated by bandpass filters and amplified to the power level 

required for radio wave propagation studies before 

transmission. 

2.3 Multi-Tone Frequency Synthesizer 

Characterization and Test Data 

A generic test setup for characterizing the K-band and the 

Q-band multi-tone frequency synthesizer circuits described 

above is presented in Figure 3. Photographs of the K-band and 

the Q-band test circuit are shown in Figures 4 and 5, 

respectively. The bandpass filters and the low noise amplifiers 

(LNAs) are appropriately selected for the two frequency 

bands. The measured K-band and Q-band spectrums are 

presented in Figures 6 and 7, respectively. A chain of MMIC 

based power amplifiers can further enhance the power levels 

such that the beacon EIRP is on the order of 30 dBW at the 

edge of CONUS coverage (Ref. 5). A minimum data 

collection period of 36 months is recommended and hence the 

above EIRP is the end of life value (Ref. 1). 
NASA/TM—2014-218122 3 

3.0 Conclusions 

The design, construction and test data for a K-band and a 

Q-band multi-tone frequency synthesizer for radio wave 

propagation studies are presented. 

References 

1. R.J. Acosta, J.A. Nessel, R.N. Simons, M.J. Zemba, J.R. 

Morse and J. Budinger, “W/V-Band RF Propagation 

Experiment Design,” 18th Ka and Broadband 

Communications Navigation and Earth Observation 

Conference Digest, pp. 355–362, Ottawa, Canada, Sept. 

24–27, 2012. 

2. Patent Application Filed with the U.S.P.T.O. 

3. R. Bauer, “Ka-band Propagation Measurements: An 

Opportunity with the Advanced Communications 

Technology Satellite (ACTS),” Proc. IEEE, vol. 85, no. 6, 

pp. 853–862, June 1997. 

4. R.J. Acosta, R. Bauer, R.J. Krawczyk, R.C. Reinhart, M.J. 

Zernic, F. Gargione, “Advanced Communications 

Technology Satellite (ACTS): Four-Year System 

Performance,” IEEE Jour. Selected Areas in 

Communications, vol. 17, no. 2, pp. 193–203, Feb. 1999. 

5. R.N. Simons and E.G. Wintucky, “Q-Band (37–41 GHz) 

Satellite Beacon Architecture for RF Propagation 

Experiments,” 2012 IEEE Antennas and Propagation 

International Symposium Digest, Chicago, IL, July 8–14, 

2012. 
REPORT DOCUMENTATION PAGE Form Approved 

OMB No. 0704-0188 

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the 

data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this 

burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. 

Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB 

control number. 

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 

1. REPORT DATE (DD-MM-YYYY)

01-04-2014 

2. REPORT TYPE

Technical Memorandum 

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies 

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Simons, Rainee, N.; Wintucky, Edwin, G. 

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

WBS 295670.01.04 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

John H. Glenn Research Center at Lewis Field 

Cleveland, Ohio 44135-3191 

8. PERFORMING ORGANIZATION

 REPORT NUMBER

E-18864 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

Washington, DC 20546-0001 

10. SPONSORING/MONITOR'S

 ACRONYM(S)

NASA 

11. SPONSORING/MONITORING

 REPORT NUMBER

NASA/TM-2014-218122 

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified-Unlimited 

Subject Category: 17 

Available electronically at http://www.sti.nasa.gov 

This publication is available from the NASA Center for AeroSpace Information, 443-757-5802

13. SUPPLEMENTARY NOTES

14. ABSTRACT

This paper presents the design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb 

generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37 to 43 

GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links. 

15. SUBJECT TERMS

Telecommunications; Space communication; Satellite communications; Microwave transmission 

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

 ABSTRACT

UU 

18. NUMBER

 OF 

 PAGES

10 

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email:help@sti.nasa.gov) 

a. REPORT

U 

b. ABSTRACT

U 

c. THIS 

PAGE

U 

19b. TELEPHONE NUMBER (include area code)

443-757-5802 

Standard Form 298 (Rev. 8-98)

Prescribed by ANSI Std. Z39-18