PD_14E-144A-RF-PD_high_power_amp_3-mar-2014.docx

14E-144A-RF

3 Mar 2014

PURCHASE DESCRIPTION

HIGH POWER AMPLIFIER SYSTEM

1.0 Scope. This Purchase Description (PD) describes a High Power Amplifier System (HPAS) which will be used in Air Force Precision Measurement Laboratories (PMEL.) Used with high power microwave power standards, the Amplifier will calibrate high power RF watt meters The Amplifier shall cover an operating frequency range of 1 to 1000 MHz with a variable output of 10-500 Watts.

2.0 Components. The components of the HPAS are the amplifiers, filters, switching networks, power supplies and RF load resistor necessary to ensure proper performance. The minimum Air Force performance requirements of these systems are set forth in the remaining paragraphs of this PD.

3.0 Performance Requirements. The HPAS shall be made up of solid state components. Tube amplifiers shall not be considered. This HPAS shall have a single output port, single input port and a sample port .

3.1 Frequency Range and Minimum Power Output. The HPAS output power shall be rated as Continuous Wave (CW) minimum, measured at the 1 dB compression point, over the specified frequency range, into 50 ohms. The HPAS shall sustain operating characteristics from 1.0 to 1000.0 MHz and shall provide an output of from 10 minimum to ≥ 500 watts, continuously variable range by adjusting the RF output level.

3.2 VSWR. The VSWR at the input port shall be ≤ 2.0: l referenced to 50 ohms, and the load VSWR at the output port shall be ≤ 2.0:1 referenced to 50 ohm, at full power output.

3.3 Output Power Stability. After the warm-up period designated in 8.5.10, the output signal shall not vary more than ± 0.05 dB in 5 minutes, with the input level held constant.

3.4 Output Power Flatness. The output signal shall not vary more than ± 1.5 dB across the entire frequency band.

3.5 Output Power Range. The output power shall be continuously variable over the entire specified range by varying the RF output level control to the amplifier. A level of no more than 0 dBm (1 mW) input to the HPAS shall result in full rated output power Levels less than 0 dBm input into the HPAS shall reduce the output power.

3.6 Signal Purity. Harmonically related signals shall be less than -50 dBc at rated power output. Non-harmonically related (spurious) signals shall be less than -60 dBc. The signal shall contain no more than 1% AM.

3.7 Connector Types. The RF input and output connector types shall be Type-N female.

3.8 Sample Port. An auxiliary (Type-N female) RF output port shall be available. This port shall make it possible to sample the RF output power of the amplifier at a level of 40 dB (nominal) below the amplifier output level.

4.0 Protective Circuitry. The HPAS shall employ the following protective circuitry:

4.1 Thermal Protection. The HPAS shall have adequate protection circuits so as to provide automatic thermal shutdown with reset, Operation shall automatically be restored when adequate cooling has occurred.

4.2 Filter Switching Error Protection. The HPAS shall have adequate protection circuits so as to provide automatic shutdown with the occurrence of a filter switching error.

4.3 Mismatch Tolerance. Protective circuitry shall be utilized to prevent HPAS damage regardless of the impedance mismatch (zero to infinity at any phase angle) on the amplifier output.

4.4 Input Overdrive Protection. The HPAS shall have adequate protection circuits so as to withstand 6 dB input overdrive under maximum rated output.

4.5 Out of Band Protection. No damage shall occur if signals outside the operating frequency range are applied to the HPAS input.

5.0 Operational Indicators. The following indicators shall be provided on the front panel:

5.1 AC Power On. There shall be an indicator identifying that the AC power is “on”.

5.2 DC Power On. There shall be an indicator identifying that the DC power is “on”.

5.3 Thermal Overload. There shall be an indicator identifying if a thermal overload has occurred.

5.4 Power Supply Fault. There shall be an indicator identifying if a power supply fault has occurred. A separate meter is not required.

5.5 Power Supply Overload. There shall be an indicator identifying if a power supply overload has occurred. A separate meter is not required.

5.6 Power Meter. There shall be a meter which indicates the power of the HPAS output. The meter shall be accurate to at least ± 15% of full scale.

5.7 Operational Time Counter. A counter shall be provided on the front panel of the HPAS for the purpose of indicating the elapsed operational time. It shall indicate time in hours (to at least 99,999 hours) and shall be accurate to at least 1 second per day. The counter shall operate any time the HPAS is powered on.

5.8 Standby Operating Mode. A standby switch shall be incorporated in the HPAS. This operating mode will facilitate the making and breaking of connections at the output port with no high power present. After switching from standby to operate, the HPAS shall not require a warm-up period. There shall be an indicator identifying if the amplifier is in the standby mode or operate mode.

5.9 Module Failure. The unit shall indicate or identify a failed module. (An internal indication shall be acceptable.)

6.0 Remote Operation (IEEE-488 GPIB Standard). A IEEE-488 GPIB standard programmable switching circuit shall be provided to control amplifier and filter selection, if the selections are not automatic.

6.1 IEEE-488 GPIB Performance Requirements. The following interface must be provided on the mainframe, IEEE-488, 1-1987 GPIB Standards with five bit address selection. The instrument shall use bi-directional data transmission in ASCII-coded format. The following list (Table 1) identifies minimum interface subset requirements for the IEEE-488, 1-1987 GPIB Standard.

Minimum Interface Requirements

Table 1.

7.0 Load Resistor. A RF coaxial load resistor shall accompany the HPAS.

7.1 Ranges. The load shall be capable of accommodating the frequency and power ranges identified in paragraph 3 of this PD.

7.2 Cooling. The load can be either air or oil (except Poly Chlorinated Biphenyls) cooled. There shall not be a requirement for any type of external cooling.

7.3 Load Connector. The load shall have Type-N male connectors.

7.4 Load Reflection Coefficient. The maximum reflection coefficient for the load input shall be 0.12 (≥ VSWR 1.15:1).

8.0 General Specifications. The following shall apply:

8.1 Safety. The equipment shall conform to MIL-PRF-28800F for laboratory type equipment. When this PD and MIL-PRF-28800F conflict, this purchase description shall govern. The design, materials and manufacture of the HPAS shall follow the best commercial safety standards and practices to ensure that it is safe for the operator and maintenance personnel throughout the life of the equipment.

8.2 Input Power Requirements. The HPAS shall operate from 208 to 240VAC rms, 50 to 60 Hz nominal as specified in MlL-PRF-28800F, a power cord with a minimum length of 6 feet, shall be provided with the system and shall meet the requirement of MIL-PRF-28800F.

8.3 Mechanical and Physical Requirements:

8.3.1 Dimensions. With the exception of the load resistor, the HPAS shall be provided in a equipment console not to exceed 23 x 36 x 70 inches (width x depth x height). Numerous consoles may be used depending on frequency ranges.

8.3.2 Weight. The HPAS shall not exceed 600 pounds total including the single bay console, and the load resistor.

8.3.3 Commercial Parts. Commercial parts and materials that are used shall have properties consistent with a precision laboratory instrument.

8.3.4 Design and Construction. The equipment shall be designed and constructed of materials that meet the requirements of this specification and in accordance with the best commercial practices for industry approved equipment. It shall be designed and manufactured to maximize reliability, maintainability, accuracy of operation, and ease of operation, all parts such as shafts, bearings, regulators, switches, controls, etc shall have proper clearance and adjustments. They shall work together so that the equipment shall supply the rated requirements without unnecessary strains, vibrations, or overheating. They shall be able to withstand the conditions met in shipping, storage, installation, and service. All material and parts of this equipment shall be capable of withstanding the environmental requirements of this specification.

8.3.4.1 Reliability. The HPAS shall meet the reliability requirements of MIL-PRF-28800F. The HPAS shall have a MTBF of 1500 hours or more for continuous or intermittent operation.

8.3.4.2 Reliability Verification Test. The contractor shall verify that the units being delivered meet the specified requirements and that the unit does not contain inherent design weaknesses.

8.3.5 Selected Components. Matched and selected components as well as specially built, nonstandard components shall not be used .

8.3.6 Environment.

8.3.6.1 Environmental Requirements. The equipment supplied shall be suitable for operating in a laboratory environment.

8.3.6.2 Operating Temperature. Electrical, electronic, and electromechanical items shall be capable of operating in an ambient temperature of 60 to 80 degrees F without loss of required performance.

8.3.6.3 Operating Humidity. The equipment shall maintain specified performance in an atmosphere from 20% to 60% relative humidity.

8.3.7 Metals. Metals shall be of the corrosion-resistant type or shall be metallurgical processed or suitably treated to resist corrosion due to atmospheric conditions likely to be met in storage, service, or transportation. Dissimilar metals in close contact with each other shall not be present. Selection of metals shall be in accordance with the applicable requirement of MIL-STD-889B.

8.3.8 Protective Covers. All exposed connectors shall be protected by reusable dust covers or caps.

8.3.9 Precision Connectors. Precision connectors shall mate nondestructively.

8.3.10 Coaxial Cable Electrical Insulation.

8.3.10.1 Prohibited Materials. Polyvinyl chloride (PVC) shall not be used as an insulating or jacketing material in electronic cable assemblies unless prior approval is obtained, The use of this polymer has been prohibited according to MIL-STD-454N (requirement 11, paragraph 4.10) and MIL-STD-1587C (paragraph 5.2.7) due to its corrosive nature during degradation.

8.3.10.2 Materials. Materials used in electronic cable and connector technology shall conform to applicable requirements in MIL-STD-454 and MIL-STD-1587 NOTI, These materials shall be selected such that they degrade by a mechanism other than elimination and shall be resistant to corrosion and reductions in performance.

8.3.11 Interchange Ability. Units and all replaceable assemblies, subassemblies, components, and parts of a designated model provided under a single contract or ordered from any one manufacturer shall be fully interchangeable without interference or degradation of performance.

8.3.12 Warm-Up Period. The equipment shall meet all specifications contained in this PD after a warm-up period not to exceed 30 minutes.

8.3.13 Continuous Operation. After the required warm-up period, the equipment shall meet the specifications of this PD and shall not display any intermittent characteristics or overheating for an extended period of not less than 8 hours of continuous operation.

8.3.14 Accessories. All accessories necessary for normal operation of the equipment shall be supplied by the contractor.

8.3.15 Model and Serial Number Identification: This item shall be clearly labeled with a model number, serial number, and manufacturer’s name. Unique item identification labeling shall follow the Item Identification and Valuation clause as stated in the clause section.

8.3.16 Workmanship: The workmanship shall be first class, of neat general appearance, and shall comply with standard commercial practices. The standards of workmanship will be such that this item shall comply with the requirements in this purchase description. All components, subassemblies, and final assembly shall comply with the examination and tests described in this purchase description’s testing paragraph.

9.0 Testing. This item will be inspected and accepted at destination as specified elsewhere in the contract. The item will be checked with test equipment whose parameters are equal to or better than those required to assure specified performance requirements are met. Test equipment used has first echelon certification directly traceable to the National Institute of Standards and Technology or other AFMETCAL approved NMI where required. Tests will be performed to assure the item meets the requirements of this purchase description. Such testing at destination does not relieve the contractor from performing all inspections and quality checks at the point of fabrication, as is specified elsewhere in the contract, or as is necessary, to assure performance as specified herein.

Attachment:

Data Requirements