The 348 series of hermetically sealed, digitally programmable, eight-bit d/a attenuators exhibit an attenuation range of 60 kB over greater than octave bands in the 2 to 18 GHz frequency range. The attenuators have a 0.25 dB resolution with guaranteed monotonicity. The 348 models switch in less than 500 ns and the 348H models switch in less than 200 ns. Units measure 1.34" square x 0.5" thick. Performance is guaranteed over a -54°C to 110°C temperature range. The attenuators are designed primarily for digital control, but they may be controlled by an analog voltage, as well, or by a combination of analog and digital control. The 348 series operates up to 100 mW of RF power without performance degradation, while the faster 348H series operates up to 10 mW. A miniature 14-pin connector is employed for both control lines and power supply lines. High Reliability screening is also available.