Fixed Coaxial Attenuators Overview V2.00 V1.01 ● ● ● ● ● dc - 1GHz, dc - 2.5 GHz, dc - 4, dc - 12.4, dc - 18 and dc - 26.5 GHz Performance Temperature Range: -54° to +125°C Temperature Coefficient: 10-4 dB/dB/°C Average Power: Up to 20 Watts Connectors: SMA, Type N, TNC Typical Performance Part No. 2082-6191-03 VSWR 1.40 1.35 1.30 VSWR Attenuators are linear, passive transmission line components designed to reduce the input power in a matched system by a predetermined amount. M/A-COM offers a complete line of fixed coaxial attenuators designed for laboratory, production, testing and system use. Typical applications include VSWR reduction at the insertion point of measurement setups, range extension of power meters, RF path loss simulation, and isolation or power level reduction of signal sources. The attenuator characteristics of primary concern are: 1.25 1.20 1.15 1.10 1.05 dc 2 4 6 8 10 a. frequency range b. attenuation c. average and peak power handling capability d. operating temperature range e. size f. weight 14 16 18 ATTENUATION 3.4 ATTENUATION (dB) 3.3 All attenuators are production tested to ensure proper operation within published specifications. Therefore, over specification by the user is unnecessary and reduces costeffectiveness. For example, if the frequency range requirements are 2 to 4 GHz, over-specifying flat performance to 12.4 GHz will increase component cost with no performance advantage. 3.2 3.1 3.0 2.9 2.8 2.7 Catalog attenuators are available in a variety of package sizes and connector configurations as shown on the following pages. The attenuator elements are designed to provide broadband operation with low frequency sensitivity and extremely stable operation at temperature extremes. dc 2 4 6 8 10 12 FREQUENCY (GHZ) OSM is a registered trademark of M/A-COM M/A-COM Division of AMP Incorporated ■ North America: Tel. (800) 366-2266, Fax (800) 618-8883 ■ Asia/Pacific: Tel. +85 2 2111 8088, Fax +85 2 2111 8087 ■ Europe: Tel. +44 (1344) 869 595, Fax +44 (1344) 300 020 www.macom.com 12 FREQUENCY (GHZ) AMP and Connecting at a Higher Level are trademarks. Specifications subject to change without notice. 4-4 14 16 18 Fixed Coaxial Attenuators Overview V2.00 Attenuation Temperature Coefficient The term attenuation is generally used rather loosely and often means insertion loss or, to be even more specific characteristic insertion loss. Insertion loss is the ratio of the power delivered to a matched load by a matched generator before and after the insertion of a component in the line. Insertion loss is actually a combination of two losses: mismatch loss (reflective) and attenuation (dissipative). Mismatch loss is the ratio of power that would be absorbed by the device if it were perfectly matched to the actual power absorbed by the device with its mismatch in impedance. Attenuation is the ratio of power into a component to the power out under perfectly matched conditions and represents the actual power dissipated within the component. Where a component is perfectly matched to the line and the load, the mismatch loss is zero, and the attenuation and insertion loss are the same. The maximum change of insertion loss in dB per °C from 20°C over the maximum operating temperature range. To obtain ∆dB, multiply the temperature coefficient by the value in dB and by the temperature change from 20°C in °C. POWER DERATING 120 100 POWER (%) 80 60 40 20 0 Average Power 0° 25° 50° 75° The maximum average power is the maximum specified input power applied for a minimum of one hour at a specified operating temperature (25°C for OSM fixed coaxial attenuators) with the output terminated in the characteristic impedance which will not permanently change the specified properties of the attenuator after return to ambient temperature at a power level 20 dB below the maximum specified input power. 125° Specifications Impedance: 50 ohms Temperature Range: -54 to +125°C Temperature Coefficient: 10-4 dB/dB/°C Custom Considerations Derating is necessary if the attenuator is operated at higher temperatures. See derating curve and specifications. In addition to the standard models described in this section, M/A-COM can supply special attenuators to suit your particular needs. Some typical specials are listed below. Complete facilities are maintained for the testing and documentation requirements of high reliability aerospace applications. Peak Power The maximum peak power at a specified pulse width and average power which when applied for a minimum of one hour while the output is terminated in the characteristic impedance will not permanently change the specified properties of the attenuator. The pulse width used to test OSM attenuators is 5 microseconds. • • • • • • • Extended frequency operation to 50 GHz Attenuation values greater than 20 dB In-between dB values — .5 dB steps High power units Narrow bandwidth, tight specification applications Special connectors and mounting configurations Drop-in chip attenuators M/A-COM Division of AMP Incorporated ■ North America: Tel. (800) 366-2266, Fax (800) 618-8883 ■ Asia/Pacific: Tel. +85 2 2111 8088, Fax +85 2 2111 8087 ■ Europe: Tel. +44 (1344) 869 595, Fax +44 (1344) 300 020 www.macom.com 100° TEMPERATURE (°C) AMP and Connecting at a Higher Level are trademarks. Specifications subject to change without notice. 4-5