# Presentation: 226791

## U.S. STUDY RADAR EMISSION MASKSA Review of the Radar Spectrum Engineering Criteria (RSEC)

**ROBERT L. HINKLE**

- United States Department of Commerce
- National Telecommunications and Information Administration
- Office of Spectrum Management

## 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.

##   RADAR CHARACTERISTICS ADDRESSED IN THE RSEC

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

## RSEC EMISSION MASK

## REVIEW OF RSEC

- 	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

## AIRPORT SURVEILLANCE RADAR(Klystron Output device)

##    RADIONAVIGATION RADAR(Coaxial Magnetron W/WO Filter)

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

##  RADIONAVIGATION RADAR(Coaxial Magnetron)

##     WEATHER RADAR(Klystron output Device)

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

## OVERRVIEW OFRSEC CHANGES BEING CONSIDEERED

-  Add the following to Group A (Exempt from RSEC).
- 	  Maritime Radionavigation 2900-3100 MHz
- 	  Aeronautical Radionavigation and Radionavigation
- 	     5350-5470 MHz
- 	  Aeronautical Radionavigation 15.4-15.7 GHz

##       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
- 	  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

## 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 

	  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 

**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
- 	  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

## 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 waveguide 	filter

**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 waveguide 	filter

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

## 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 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.