Traveling Wave Tubes

A traveling wave tube (TWT) is an electron device used for radio frequency (RF) amplification at microwave frequencies (above 500 MHz) and is the primary means of signal amplification utilized in communication satellites. TWTs are also used for ground broadcast stations, guidance systems and military aircraft radar. TWTs convert DC power to RF power by synchronizing the RF wave with an electron beam traveling in a vacuum.

If you listen to XM satellite radio, pay for gasoline with a credit card, watch DIRECTV® satellite television programming, make long-distance telephone calls, or watch TV broadcasts from other parts of the world (e.g., live sports events or news), our TWT products helped to make those things possible!

Traveling Wave Tube Designs

All modern designs incorporate this unparalleled experience, ensuring high reliability and optimized performance in harsh environments.

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Primarily used in ground-based or airborne radar applications, L3Harris' coupled cavity TWTs are available at power levels up to 150 kW peak—5 kW average—in X-, Ku-, Ka-Bands.

Model	Frequency Range (GHz)	Output Power (kW)	Duty (%)	Cathode Voltage (kV)	Cathode Currrent (Amps)	Saturated Gain (dB)	Cooling	Collector Voltage (kV)
L6060	9.2 to 10.2	60	3.5	-34.5	7.6	45	Liquid	24.5/17.9
L5906	9.4 to 10	50	1.0	-34	7	55	Air	21.6/15.5
L5810	9.5 to 10	15	0.4	-22.8 to -25	4	60	Liquid	12 to 14
L5844	9.7 to 9.9	20	1.5	-23	4.5	60	Air	12.5
L5652	9.8 to 10.3	40	3.5	-35	6	60	Liquid	20.65/13.3/9.1
L5649	16 to 17	50	0.3	-37	6	50	Air	Ground

L3Harris is an industry leader in the design and manufacture of pulsed and CW helix and ring loop TWTs for radar, electronic warfare (EW) and missile applications.

These TWTs operate in standard bands over the 2 to 18 GHz frequency range and provide superior performance and reliability.

Model	Frequency (GHz)	Output Power (kW)	Duty Cycle (%)	Gain (dB)	Cathode Voltage (kV)	Cathode Currrent (Amps)	Collector Voltages (kV)	RF Output Connector	Weight (Pounds)
L5714	2 to 2.6	20	0.4	45	-20	5.2	Ground	7/8" coax	30.0
L2086	2 to 4	0.5	CW	30	-5.6	0.77	4	SC	14.0
L5843	7 to 16.5	0.3	7	48	-6.35	0.735	4.55	TNC	2.3
L6113	8 to 10	1	5	31	-7.5	1	5.36/4.25/2.06	TNC	2.5
L5850	8.5 to 10.5	2	6	60	-11	1.4	7.7	WR-90	7.7
L6028	8.7 to 9.4	8	2.5	60	-15	2.6	10.5	WR-90	4.5

L3Harris manufactures a line of ring bar TWTs in UHF and L-Bands with output powers up to 200 kW.

These TWTs are used in long-range array radars such as the FPS-108 Cobra Dane system, the PARCS space surveillance radar, U.S. and foreign shipboard surveillance radars and airport surveillance radars.

Specifications on High Power TWTs

Frequency
Product Number	Frequency MHz	Output Power Peak kW	Output Power Average Watts	Cathode Voltage kV	Cathode Current Amps	RF Duty Cycle %	Basic Electronic Efficiency %
L-4920	420–450	175	10,500	40	14.0	6	40
L-4922	1200–1415	140*	6,000	40	13.0	3.6	35
L-4923	1175–1375	175	10,500	42	14.0	6	33
L -4950	3100–3500	125	2,500	40	12.0	2	35
L-4966	1250–1350	155	6,000	40	14.5	3.6	36
L-4995	850–1050	150	6,000	40	15.0	3.75	32
*Peak power levels of 200 (kW) are available in this frequency range

Prime Power Considerations
Product #	Cathode Volt. kV	Cathode Cur. Amps	Grid Drive Volt. V	Grid Bias Volt. V	Grid Cur. mA	Heater Volt. V	Heater Cur. Amps	1st Stage Col. Cur. kV	1st Stage Col. Cur. Amps	2nd Stage Col. Volt. kV	2nd Stage Col. Cur. Amps
L-4920	40	14	1,300	-750	25.0	28	4	-12	12	-5	2
L-4922	40	13	1,250	-750	10.0	28	4	0	12.8	N/A	N/A
L-4923	42	14	1,200	-750	14.0	28	4	-9	10	-3	4
L-4950	40	12	1,200	-750	10.0	28	4	0	11.8	N/A	N/A
L-4966	40	14.5	1,400	-750	14.0	28	4	0	14.3	N/A	N/A
L-4995	40	15	1,300	-750	14.0	28	4	0	14.8	N/A	N/A

Electron Beam Focusing
Product #	Method	Solenoid Volt. V	Solenoid Cur. Amps	Slenoid Resistance Ohms	Max Prime Power Watts	Max DC Intercept Cur. mA	Max RF Intercept Cur. mA	Coolant
L-4920	INTEGRAL	72	13	5	1200.0	250	1250	WATER
L-4922	INTEGRAL	80	13	4.5	1100.0	200	400	WATER
L-4923	EXTERNAL	20	20	N/A	500.0	100	200	WATER
L-4950	INTEGRAL	50	13	5	1000.0	200	500	WATER
L-4966	INTEGRAL	80	13	4.5	1100.0	100	150	WATER
L-4995	INTEGRAL	80	13	4.5	1100.0	100	350	WATER

Extended RF Parameters
Product #	Small Signal Gain dB	AM Noise dB	PM Noise dB	Noise Poer Output dBm/MHz	2nd Harm. dBc	Insertion Loss dB	Max RF Intercept Cur. mA	Coolant
L-4920	40	-80	-80	-107	-26	90.0	2000	25
L-4922	40	-80	-80	-107	-26	90.0	70	5
L-4923	40	-80	-80	-107	-26	90.0	2000	2
L-4950	40	-80	-80	-107	-26	90.0	500	2
L-4966	40	-80	-80	-107	-26	90.0	70	5
L-4995	40	-80	-80	-107	-26	90.0	300	10

Physical Description
Product #	RF Input Con.	RF Output Conf.	Overall Length inches	Body Diameter inches	Weight lbs	RF Output Press. psia	Coolant Con.
L-4920	SC	3-1/8 Coax	140	12	350	15	Quick Disconnect
L-4922	N	WR650	76	10	240	20	Quick Disconnect
L-4923	N	WR650-Half Height	68	9	110	15	Quick Disconnect
L-4950	N	WR284	55	10	120	20	Quick Disconnect
L-4966	SC	WR650	76	10	240	25	Quick Disconnect
L-4995	SC	WR975-Half Height	76	10	235	25	Quick Disconnect

Design Notes:

All tubes are control grid modulated and also incorporate a shadow grid to assist in the suppression of grid emission and grid intercept current.
All L3Harris' TWTs are inherently capable of dual-stage collector depression should it be necessary to fulfill a particular system requirement.
A mod anode connection is provided on all TWTs and may be utilized to accommodate system sensing circuits and also reduce the potential damage incurrred by cathode-to-anode high-voltage arcs. This protection is accomplished through the incorporation of an external anode-to-ground resistance of two kilohms.
All cathode and collector voltages are referenced to ground.

Model	Frequency Range GHz	Output Power Watts	Small Signal Gain dB	Cathode Voltage kV	Cathode Current mA	Collector Voltage kV
L-6120	26 to 36	100	27	-8.50	140	3.40/2.15/0.85
L-6122	30 to 36	50	30	-7.10	110	2.80/2.10/1.40
L-6112	40 to 46	40	30	-7.60	110	2.80/2.10/1.40

L3Harris has a complete line of mini-TWTs, covering multi-octave bandwidths over the 2 to 46 GHz frequency range with output powers of up to 200 watts.

The tubes have multi-stage collectors for high efficiency, are of rugged thermal design, and offer long life through superior gun optics and beam magnetics. A special line of low-gain, high-efficiency micro-TWTs have been developed for use in microwave power modules (MPMs).

Model	Frequency Range (GHz)	Output Power (Watts)	Small Signal Gain (dB)	Cathode Voltage (kV)	Cathode Currrent (mA)	Collector Voltages (kV)
L6115	2 to 6	65	21	-2.67	180	2.02/1.52/0.81
L6066	4.5 to 18	35	30	-4.55	180	2.40/1.55
L6072	6 to 18	40	50	-3.90	135	1.90
L5928	6 to 18	65	46	-4.47	165	2.25
L6074	6 to 18	65	23	-3.80	155	2.25/1.95/0.72
L6130	6 to 18	100 to 125	20	-4.20	220	2.50/1.95/1.22/0.62
L6139	6 to 18	100 to 125	25	-4.20	220	2.55/1.70/1.06/0.63
L6152	6 to 18	200	30	-5.85	290	3.51/2.34/1.36
L5990	10 to 10.5	130	27	-4.10	165	2.25
L6108	13.75 to 14.5	90	38	-5.02	120	2.45/1.55
L6120	29 to 38	90	25	-8.50	120	3.40/2.12/0.85
L6122	30 to 36	50	30	-7.10	110	2.80/2.10/1.40
L6112	40 to 46	40	30	-7.60	110	2.80/2.10/1.40

L3Harris’ space traveling wave tubes (TWTs) are key components for communications satellites.

L3Harris has delivered more than 4,700 space TWTs and has over five decades of experience with developing TWTs for space-based applications.

Model	Band	Pout	Approx. Efficiency	Approx. Mass	Delivered	In Orbit
83200H	L	80 to 250 W	63 to 70%	3500 g	4	4
8412HxR	S	100 to 140 W	62 to 65%	1270 g	573	343
84250Hx/HxR	S	200 to 300 W	65 to 74%	3200/3550 g	82	0
8555Hx	C	20 to 120 W	65 to 69%	790 g	701	627
85100HxR	C	80 to 140 W	64 to 68%	1165 g	16	12
86160Hx	X	40 to 160 W	63 to 67%	895 g	201	156
86160HxR	X	100 to 160 W	64 to 69%	1250 g	39	19
88150Hx	Ku	35 to 205 W	60 to 71%	695 g	416	310
88150HxR	Ku	35 to 180 W	60 to 71%	950 g	2,195	1,622
9110Hx*	K	40 to 140 W	58 to 68%	770 g	110	35
9110HxR*	K	40 to 140 W	63 to 68%	995 g	343	70
9250Hx/HxR	K	150 to 300 W	63 to 68%	1400/1700 g	0	0
99xxH	Ka/Q/V	10 to 200 W	30 to 60%	1500 g	36	5
TOTAL					4,719	3,203
* - 9110Hx/HxR quantities include the 9100Hx/HxR
Modern TWTs In Orbit: > 3500 (> 155 million hours, Spot FIT Rate: < 150)