# Presentation: 572918

## RADAR SPECTRUM ENGINEERING CRITERIA(RSEC)A Comprehensive Review 

**ROBERT L. HINKLE**

- Alion Science and Technology
- 185 Admiral Cochrane Drive
- Annapolis, MD 21401

## PURPOSE

- ●	Ensure an acceptable degree of electromagnetic compatibility among radar systems, and between such systems and those of other radio services sharing the frequency spectrum.
-  ●	 Promote efficient use of the spectrum.

## REASON FOR RSEC REVIEW
●Last major review of RSEC conducted in 1973-1977 time frame
●	New generation of radar systems more complex
	  Waveform characteristics change pulse-to-pulse
	  	Dynamic PRF pulse trains
●	Trend toward solid state output devices
●	Increase in interference from radars
● 	ITU-R Working Party 8B (Radiodetermination) has set up a radar group to investigate feasibility of more stringent emission masks than contained in ITU-R Recommendation SM1541, Annex 8, by 2006 Radiocommunication Assembly meeting.

	  	Work Program developed by ITU-R Working Party 8B

- ●Last major review of RSEC conducted in 1973-1977 time frame
- ●	New generation of radar systems more complex
- 	  Waveform characteristics change pulse-to-pulse
- 	  	Dynamic PRF pulse trains
- ●	Trend toward solid state output devices
- ●	Increase in interference from radars
- ● 	ITU-R Working Party 8B (Radiodetermination) has set up a radar group to investigate feasibility of more stringent emission masks than contained in ITU-R Recommendation SM1541, Annex 8, by 2006 Radiocommunication Assembly meeting.
- 	  	Work Program developed by ITU-R Working Party 8B

## APPROACH
 	Develop a software program that will provide current and optional emission masks.

	Identify, through measurements, emission characteristic of radars with various types of output devices, filters and antennas.

Apply software program (emission masks) to measured emission characteristics to assess feasibility of establishing a more spectrum efficient emission mask.

Engage the radar manufacturers and radar output device manufacturers to identify state-of-the-art capabilities.

Through the IRAC/TSC, in coordination with Federal agencies, reach agreement regarding draft revised emission masks for future radar systems.  This coordination is in progress.

-  	Develop a software program that will provide current and optional emission masks.
- 	Identify, through measurements, emission characteristic of radars with various types of output devices, filters and antennas.
- Apply software program (emission masks) to measured emission characteristics to assess feasibility of establishing a more spectrum efficient emission mask.
- Engage the radar manufacturers and radar output device manufacturers to identify state-of-the-art capabilities.
- Through the IRAC/TSC, in coordination with Federal agencies, reach agreement regarding draft revised emission masks for future radar systems.  This coordination is in progress.

## RADAR CHARACTERISTICS ADDRESSED IN THE RSEC

● 		Emission bandwidth (40 dB)
●		Emission levels 
●		Tuning Range
●		Antenna patterns
●		Frequency tolerance
●		Receiver selectivity
●		Image and spurious rejection
●		Local-oscillator radiation

- ● 		Emission bandwidth (40 dB)
- ●		Emission levels
- ●		Tuning Range
- ●		Antenna patterns
- ●		Frequency tolerance
- ●		Receiver selectivity
- ●		Image and spurious rejection
- ●		Local-oscillator radiation

## RSEC EMISSION MASK

## AIRPORT SURVEILLANCE RADAR(Klystron Output device)

- (radiated measurement in far field of antenna)

##     WEATHER RADAR(Klystron output Device)

**    ****WEATHER RADAR****(Klystron output Device)**

- (radiated measurement in far field of antenna)

##    RADIONAVIGATION RADAR  (Coaxial Magnetron WO Filter)

**   ****RADIONAVIGATION RADAR****  (Coaxial Magnetron WO Filter)**

- (radiated measurement in far field of antenna)

## RADIONAVIGATION RADAR(Coaxial Magnetron With Filter)

**RADIONAVIGATION RADAR****(Coaxial Magnetron With Filter)**

- (radiated measurement in far field of antenna)

##  RADIONAVIGATION RADAR(Coaxial Magnetron, Slotted Array Antenna)

- (radiated measurement in far field of antenna)

## OVERVIEW OFRSEC CHANGES BEING CONSIDERED

- ● Add the following to Group A (Exempt from RSEC).
- 	  Maritime Radionavigation 2900-3100 MHz
- 	  Radionavigation 5460-5650 MHz
- 	  Aeronautical Radionavigation 15.4-15.7 GHz
- These radars are, for the most part, not under Government control and are widely used by the private sector.

##       OVERVIEW OF 

**      ****OVERVIEW OF **
**RSEC CHANGES BEING CONSIDERED**
- ●	Group B (Criteria B)
- 	 Retain 40 dB bandwidth formulas
-         Assess feasibility of roll-off slopes of 30/40 dB per decade
-         Propose to change X (dB) floor level to:
- 		X (dB) =10LogP(Watts) + 30
- 		Where: 60 dB ≤ X (dB) ≤ 80 dB
-        Current RSEC (X) level is dependent on the power, pulse width, and prf of the radar (see section 5.5.2 of NTIA Manual of Regulations & Procedures for Federal Radio Frequency Management).

## OVERVIEW OF                    
RSEC CHANGES BEING CONSIDERED

●	Group C (Criteria C)
	  Retain 40 dB bandwidth formulas
	  Assess feasibility of  roll-off slopes of 30/40 dB per decade 
	  Propose to change X (dB) Level to 60 dB for near term, and consider  phasing in X (dB) floor of:

			X (dB) =10LogP(Watts) + 30
			Where: 60 dB ≤ X (dB) ≤ 80 dB 

     Current RSEC (X) level is dependent on the power, pulse width, and prf of the radar (see section 5.5.3 of NTIA Manual of Regulations & Procedures for Federal Radio Frequency Management).

**RSEC CHANGES BEING CONSIDERED**
- ●	Group C (Criteria C)
- 	  Retain 40 dB bandwidth formulas
- 	  Assess feasibility of  roll-off slopes of 30/40 dB per decade
- 	  Propose to change X (dB) Level to 60 dB for near term, and consider  phasing in X (dB) floor of:
- 			X (dB) =10LogP(Watts) + 30
- 			Where: 60 dB ≤ X (dB) ≤ 80 dB
-      Current RSEC (X) level is dependent on the power, pulse width, and prf of the radar (see section 5.5.3 of NTIA Manual of Regulations & Procedures for Federal Radio Frequency Management).

## OVERVIEW OF                    
RSEC CHANGES BEING CONSIDERED

●	Group D (Criteria D)

	 Retain all of Criteria D except change harmonic levels to 80   	dB

	 New solid state radars can not meet Criteria D without filters

**RSEC CHANGES BEING CONSIDERED**
- ●	Group D (Criteria D)
- 	 Retain all of Criteria D except change harmonic levels to 80   	dB
- 	 New solid state radars can not meet Criteria D without filters

- ● 	Group E (Criteria E)
-      	 No proposed changes

## RELATED ITU-R ACTIVITIES

Proposed Formation of JRG 1A/1C/8B

Rec.  ITU-R SM.1541: Out-of-Band emissions

Rec. ITU-R M.1314: Methods to reduce radar unwanted emissions

Recommendation ITU-R M.1177: Techniques for measurement of radar unwanted emissions    

- Proposed Formation of JRG 1A/1C/8B
- Rec.  ITU-R SM.1541: Out-of-Band emissions
- Rec. ITU-R M.1314: Methods to reduce radar unwanted emissions
- Recommendation ITU-R M.1177: Techniques for measurement of radar unwanted emissions

- 