## JRG-64 Rev3

Ref: JRG-43

February 20, 2006

## JRG 1A-1C-8B Work Program

1\. Background

Unwanted emission masks in the out-of-band domain for primary radar
systems are contained in Recommendation ITU-R SM.1541, Annex 8. The
ITU-R out-of-band emission masks for primary radar systems are intended
to recommend an acceptable degree of electromagnetic compatibility among
radar systems, and between such systems and those of other radio
services sharing the frequency spectrum.

In the development of the out-of-band emission masks for primary radar
systems, it was the view of several administrations that there was a
need to further investigate the state-of-the-art radar systems and their
ability to suppress unwanted emissions. This review of radar unwanted
emissions in the out-of-band domain is to be completed by 2006. See
Recommendation ITU-R SM.1541, Annex 8, Note 3. The outstanding issue
concerns the "design objectives" highlighted in this document. This
"design objective" concerns the possibility of making more stringent the
requirement for radars with regard to the "roll-off\" of out‑of-band
(OOB) emissions.

The outcome of this study may result in revisions to Recommendation
ITU-R SM.1539, which addresses the boundary between the out-of-band and
spurious domains, Recommendation ITU‑R SM.1541, which addresses
out-of-band emissions domain, and Recommendation ITU‑R SM.853, which
addresses the necessary bandwidth.

Pursuant to initiating this study, Working Party 8B revised Question
202/8 to provide guidance to administrations in conducting their
investigation.

2\. Objective

The objective of this work program is to review the current ITU-R limits
for unwanted emissions in the out-of-band domain contained in Annex 8 of
Recommendation ITU-R SM.1541, and assess the feasibility of establishing
guidance to promote more effective and efficient use of the spectrum.

3\. Approach

In order to accomplish the above objective, the following tasks will be
undertaken:

a\) Develop a software tool that will provide current ITU-R emission
masks and alternative emission masks for comparison with measured radar
emission data.

b\) Review the current necessary bandwidth (-20 dB) formulas and --40 dB
bandwidth formulas for the various types of modulations used by radar
systems, and develop new formulas as appropriate.

c\) Identify, through measurements, characteristic radar emission
spectra considering such parameters as: waveforms (e.g. pulse shape and
modulation); types of output devices; RF filter technologies; and
antenna types.

d\) Analyze the measured emission characteristics to assess the
feasibility of establishing more spectrum efficient emission masks.

e\) Discuss draft revised emission masks, and identify state-of-the-art
capabilities which may allow radars to operate more efficiently while
recognizing economic impacts and mission requirements to achieve
efficient and effective operation.

f\) Draft a Final Report, including Working Documents Towards
Preliminary DRAFT Revisions of Recommendations ITU-R SM.1541, Annex 8,
ITU-R SM.853, and ITU-R SM.1539, and provide the results of these
studies to Working Party 1A, 1C and 8B. See Document JRG-63.

4.  Specific areas requiring studies

### The following are specific areas requiring studies. Drafting groups and action items have been established to address items listed below. Information on the drafting groups and action items are addressed in Sections 5 and 6, respectively. 

1)  Develop a software tool that will provide current ITU-R emission
    masks and alternative emission masks for comparison with measured
    radar emission data. See documents: JRG-2, 3, 4, 5, 29, 30, 31, and
    60.

2)  Review the necessary bandwidth (-20 dB) and --40 dB bandwidth
    formulas given in ITU-R SM.1541, develop new formulas as
    appropriate, particularly for the following types of modulations and
    validate them through measurements to establish implementation
    factors (Priority 1):

    a.  Non-FM pulses (unmodulated pulses), including radars using
        magnetrons with low pulse width to rise time ratio (Doc. JRG-7,
        9, 10, 35 rev.1).

    b.  FM-pulsed modulated waveforms, including: linear, non-linear.
        Analysis and measurements have shown that the current formulas
        especially for FM-pulsed modulated waveforms are too generous
        for large time-bandwidth products (compression ratios). (Doc.
        JRG-7, 10, 12, 13, 17, 19, 21, 32, 33, 37, 38, 54, 55 and 56)

    c.  FMCW, including radars operating at long wavelengths. Analysis
        indicates that the current --40 dB bandwidth formula for FMCW
        modulated waveforms may not be representative for all cases.
        (Doc. JRG-7, 39, 50)

    d.  Phase-coded pulses (PSK/QPSK, MSK/GMSK, and Taylor quadriphase),
        phase-coded CW, (Doc. JRG-7).

3)  Identify, through analysis and measurements, the achievable roll-off
    from the --40 dB bandwidth for the following output devices as a
    function of the class of amplification (Priority 2):

    a.  cross-field (Doc. JRG-14, 16, 20, 22, 34, 40, 42, 52)

    b.  linear beam (Doc. JRG-7 and 57)

    c.  solid state (Doc. JRG-36 and 39).

4)  Investigate the feasibility of implementing pulse shaping and
    filters between solid state Transmit-Receive (T/R) Modules and the
    antenna elements. These studies should consider the type of platform
    (e.g. ground based, ship borne, airborne, space borne) (Doc. JRG-7
    and 33) (Priority 1).

5)  Review the definition and description of rise and fall time (Note 1
    of Annex 8 of Rec. ITU-R SM.1541). Measurements have shown that the
    pulse forms are sometimes not nearly trapezoidal, especially for
    radars using magnetrons that tend to overshoot the maximum level for
    a very short time at the beginning of the pulse (Priority 2).

6)  Determine the characteristics of airborne radar systems (Doc.
    JRG-41), obtain emission spectrum measurements on representative
    airborne systems with different output devices, and identify factors
    that could affect the emission spectrum (Doc. JRG-41) (Priority 1).

7\) Impact of ITU-R out-of-band emission limits on radars operating at
long wavelengths (Doc. JRG-39) (Priority 1).

Priority 1 Milestones are due September 1, 2006, and

Priority 2 Milestones are due February 15, 2007.

5\. Drafting groups

Four drafting groups have been formed. Correspondence for the drafting
groups will be conducted via e-mail. Drafting Group leads will establish
e-mail groups.

The Terms-of-Reference and lead contacts for the above JRG Drafting
Groups are given below.

##### [5.1 JRG-DG1: FMCW Modulated Waveforms]{.underline}

Terms-of-Reference

1.  Review the current necessary bandwidth (-20 dB) and --40 dB
    bandwidth formulas for FMCW modulated waveforms; and, if
    appropriate, recommend more representative formulas. Priority 1.

2.  Clarify the definition of frequency deviation (B~d~) for FMCW
    waveforms. Priority 1

3.  Review the feasibility of the application of a 40 dB/decade roll-off
    from the --40 dB bandwidth for practical combinations of waveform
    parameters. Priority 2.

Priority 1 Milestone: September 1, 2006

Priority 2 Milestone: February 15, 2007

Relevant JRG Contributions: JRG-39, 50, 58, 59

Lead contact: Leith Mudge, Australia

E-mail address: Leith.Mudge@defence.gov.au

##### [5.2 JRG-DG2: FM-Pulse Modulated Waveforms]{.underline}

Terms-of-Reference

1.  Review the current necessary bandwidth (-20 dB) and --40 dB
    bandwidth formulas for FM-pulse modulated waveforms; and, if
    appropriate, recommend more representative formulas. Priority 1.

2.  Review the feasibility of the application of a 40 dB/decade roll-off
    from the ‑40 dB bandwidth with these new formulas for practical
    combinations of waveform parameters. Priority 2.

Priority 1 Milestone: September 1, 2006

Priority 2 Milestone: February 15, 2007

Relevant JRG Contributions: JRG-7, 10, 12, 13, 17, 19, 21, 32, 33, 37,
38, 54, 55 and 56)

Lead contact: Larry Brunson, U.S.

E-mail address: lbrunson@ntia.doc.gov

**[5.3 JRG-DG3: Magnetron Emission Masks:]{.underline}**

Terms-of-Reference

1\. Review the measured magnetron emission spectrum data to determine
whether there is sufficient data to reach a conclusion on whether more
stringent masks are achievable. Priority 1.

Priority 1 Milestone: September 1, 2006

Relevant JRG Contributions: JRG-14, 16, 20, 22, 40, 42, 52

Lead contact: Adil Abbas, U.K.

E-mail address: adil.abbas@raymarine.com

##### 

##### [5.4 JRG-DG4: Phase Coded Waveforms]{.underline}

Terms-of-Reference

1.  Review the current necessary bandwidth (-20 dB) and --40 dB
    bandwidth formulas for phase coded pulse and phase coded CW
    modulated waveforms; and, if appropriate, recommend more
    representative formulas. Priority 1.

2\. Review the feasibility of the application of a 40 dB/decade roll-off
from the --40 dB bandwidth with these new formulas for practical
combinations of waveform parameters. Priority 2.

Priority 1 Milestone: September 1, 2006

Priority 2 Milestone: February 15, 2007

Lead contact: t. b. d.

6\. Action items

Seven action items have been identified. A description of the action
items and the administration responsible for the tasks are provided in
the following table.

+---+----------------------+------------+------------+----------------+
| T | Description          | Admin      | Milestone  | Status         |
| a |                      | istration/ |            |                |
| s |                      | Sector     |            |                |
| k |                      | Member     |            |                |
|   |                      |            |            |                |
| N |                      |            |            |                |
| o |                      |            |            |                |
| . |                      |            |            |                |
+---+----------------------+------------+------------+----------------+
| 1 | Provide a draft      |            |            |                |
|   | paper on radar       |            |            |                |
|   | architecture related |            |            |                |
|   | to pulse shaping to  |            |            |                |
|   | improve unwanted     |            |            |                |
|   | emission spectrum.   |            |            |                |
+---+----------------------+------------+------------+----------------+
| 2 | Provide a draft      | \[U.K.     | September  |                |
|   | paper on radar       |            | 1, 2006    |                |
|   | architecture related | John       |            |                |
|   | to the ability to    | Holloway\] |            |                |
|   | provide filtering to |            |            |                |
|   | improve unwanted     |            |            |                |
|   | emission spectrum.   |            |            |                |
+---+----------------------+------------+------------+----------------+
| 3 | Provide a paper on   | U.S.       | September  | Completed.\    |
|   | ITU-R                |            | 2005       | See JRG-47     |
|   | RadioRegulations     | Robert     |            |                |
|   | pertaining to the    | Hinkle     |            |                |
|   | requirement to       |            |            |                |
|   | contain the          |            |            |                |
|   | necessary bandwidth  |            |            |                |
|   | within the allocated |            |            |                |
|   | band.                |            |            |                |
+---+----------------------+------------+------------+----------------+
| 4 | Measurement of       | N          | September  |                |
|   | emission spectra of  | etherlands | 1, 2006    |                |
|   | linear beam output   |            |            |                |
|   | devices for various  | Bjorn      |            |                |
|   | modulations (Non-FM  | Rommen     |            |                |
|   | pulse, FM pulse      |            |            |                |
|   | etc.).               |            |            |                |
+---+----------------------+------------+------------+----------------+
| 5 | Observations of the  | U.S.       | October    | Completed.\    |
|   | effects of rise time |            | 2005       | See JRG-54     |
|   | on FM pulse spectrum | Larry      |            |                |
|   |                      | Brunson    |            |                |
+---+----------------------+------------+------------+----------------+
| 6 | Convert ITU-R radar  | U.S.       | October    | Beta version:  |
|   | emission mask model  |            | 2005       | JRG-60         |
|   | (JRG-30) into a      | Fred Najmy |            |                |
|   | Visual Studio.NET    |            |            |                |
|   | program.             |            |            |                |
+---+----------------------+------------+------------+----------------+
| 7 | Measurements of      | All        | September  |                |
|   | magnetron emission   | admin      | 1, 2006    |                |
|   | characteristics. See | istrations |            |                |
|   | table below.         | requested  |            |                |
|   |                      | to         |            |                |
|   |                      | p          |            |                |
|   |                      | articipate |            |                |
+---+----------------------+------------+------------+----------------+

# 6.1 [Measurements needed by JRG (updated: 20-Jan-06)]{.underline}

For the following classes of mobile radars using magnetrons spectrum
measurement data is needed to conclude on the possibility to meet a 40
dB/decade roll-off:

+------------+--------------+--------+------+---------+--------------+
| **R        | **D          | **     | **   | **      | **Source**   |
| eference** | escription** | Output | Peak | Minimum |              |
|            |              | de     | P    | Pulse   |              |
| **System   | **RD/RL**    | vice** | ower | width   |              |
| M.\[8B\]** |              |        | (k   | (µS)**  |              |
|            |              |        | W)** |         |              |
| **8 --10   |              |        |      |         |              |
| GHz**      |              |        |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| A2         | Airborne     | T      | 220  | 0.5     |              |
|            | search radar | unable |      |         |              |
|            |              | mag    |      |         |              |
|            | (RD)         | netron |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| A3         | Ground       | Cavity | 95   | 0.5     |              |
|            | mapping      | tuned  |      |         |              |
|            |              | mag    |      |         |              |
|            | (RD)         | netron |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| A9         | We           | Fixed  | 25   | 0.2     | Possible US  |
|            | ather/Search | Mag    |      |         |              |
|            | and          | netron |      |         |              |
|            | re           |        |      |         |              |
|            | scue/mapping |        |      |         |              |
|            |              |        |      |         |              |
|            | (RD)         |        |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| S1         | Searc        | Fixed  | 35   | 0.1     |              |
|            | h/navigation | Mag    |      |         |              |
|            | (RD)         | netron |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| S4         | Rad          | Fixed  | 50   | 0.03    |              |
|            | ionavigation | Mag    |      |         |              |
|            | (RD)         | netron |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| G1         | Airborne     | Fixed  | 0.3  | 0.3     |              |
|            | Beacon       | Mag    |      |         |              |
|            | transponder  | netron |      |         |              |
|            | (RD)         |        |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| **R        | **D          | **     | **   | **      |              |
| eference** | escription** | Output | Peak | Minimum |              |
|            |              | de     | P    | Pulse   |              |
| **System   |              | vice** | ower | width   |              |
| M.1638**   |              |        | (k   | (µS)**  |              |
|            |              |        | W)** |         |              |
| **         |              |        |      |         |              |
| (5250-5850 |              |        |      |         |              |
| M)**       |              |        |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| A          | Me           | C      | 250  | 2.0     | US           |
|            | teorological | oaxial |      |         |              |
|            |              | mag    |      |         |              |
|            | Ground/ship  | netron |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| B          | Me           | C      | 70   | 6.0     |              |
|            | teorological | oaxial |      |         |              |
|            | Airborne     | mag    |      |         |              |
|            |              | netron |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| D          | Aeronautical | Fixed  | 0.2  | 1.0     |              |
|            | Airborne     | Mag    |      |         |              |
|            | (radi        | netron |      |         |              |
|            | onavigation) |        |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| **R        | **D          | **     | **   | **      |              |
| eference** | escription** | Output | Peak | Minimum |              |
|            |              | de     | P    | Pulse   |              |
| **ITU      |              | vice** | ower | width   |              |
| RM.1460**  |              |        | (k   | (µS)**  |              |
|            |              |        | W)** |         |              |
| **         |              |        |      |         |              |
| (2900-3100 |              |        |      |         |              |
| M)**       |              |        |      |         |              |
+------------+--------------+--------+------+---------+--------------+
| IMO/       | Maritime     | Fixed  | 75   | 0.05    | Possible US  |
|            | rad          | Mag    |      |         |              |
| Fishing    | ionavigation | netron |      |         | Possible     |
|            |              |        |      |         | Japan        |
|            | (shipborne)  |        |      |         |              |
|            |              |        |      |         | Possible UK  |
+------------+--------------+--------+------+---------+--------------+

7\. Next meeting date / location and aims

4^th^ meeting: November 14-16, 2006. Hosted by Germany

a.  Further structuring of final report

b.  Further work on proposed revisions of Rec. ITU-R SM.1541, SM.853 and
    SM.1539

c.  Approve -20 and -40 dB bandwidth equations

5^th^ meeting: April 24-26, 2007. Hosted by the UK

a.  Further structuring of final report

b.  Further work on proposed revisions of Rec. ITU-R SM.1541 and SM.853

c.  Approve achievable roll-off from the -40 dB bandwidth

d.  Finalize all work.