hf/rf ZONE Products for the week of November 25 2002
Agilent Technologies says . . .
MDA-1220-08S: Smallest Hermetically Sealed SMT Optical
Driver Amp
Industry's First Miniature Surface Mount Amplifier to Provide
RF Shielding in Hermetically Sealed, Compact Package Offers NEMs Ease of
Integration and Reduced Costs for 10 Gb/s Fiber Optic Communication Systems
Agilent Technologies Inc. introduced the industry's smallest hermetically sealed surface mount optical driver amplifier specifically designed for use in OC-192/STM-64 10 Gb/s SONET/SDH fiber optic communication systems. The Agilent MDA-1220-08S is also the industry's first surface mount modulator driver amplifier to provide radio frequency (RF) shielding in a hermetically sealed small form factor package, and offers network equipment manufacturers (NEMs) ease of integration and reduced costs.
"Agilent's hermetically sealed, RF shielded package ensures that the SONET/SDH system will be reliable and will meet mandated electromagnetic interference specifications," said Bryan Ingram, vice president and general manager of Agilent's Wireless Semiconductor Division. "Our significant size advantage, increased reliability and excellent EMI performance enable our customers to reduce the cost of manufacturing new fiber optic systems."
Optical modulator driver amplifiers convert low-level electrical data into sufficient power levels to drive optical modulators without adding signal distortion. Traditionally, hermetic modulator drivers have been supplied in a metal housing with SMA connectors on both ends and a connector for mounting the driver to the board. The Agilent MDA-1220-08S is supplied in a 17.247 mm by 11.354 mm by 4.318 mm (0.679 inches by 0.447 inches by 0.170 inches) hermetic surface mount package, which is up to 80 percent smaller than the traditional hermetic metal housing.
The Agilent MDA-1220-08S can be used in OC-192/STM-64 communication system applications with or without forward-error correction (FEC) protocols. The amplifier offers wide bandwidth operation of 30 kHz to 15 GHz. Using advanced GaAs technology, it will drive both electro-absorption (EA) and lithium niobate (LiNbO3) Mach-Zehnder electro-optic modulators. This amplifier is designed for use between multiplexer (MUX) chips and the modulator to amplify non-return to zero (NRZ) or return-to-zero (RZ) signals from 9.953 Gb/s to 12.5 Gb/s.
Its standard performance characteristics include 20 dB typical gain,
an output voltage of up to 7.5V peak-to-peak into a 50 ohm optical modulator
load, 15 ps rise time, and +/- 1.5 dB gain ripple. The amplifier provides
both crossover point and output power control for maximum design flexibility.
analogZONE Says . . .
The MDA-1220-08S is designed as the data driver for OC-192 EA or LiNbO3 modulators although its frequency response greatly exceeds that need, extending from 30 kHz to 15 GHz. But it is the size of the package that is outstanding here - a hermetically-sealed 8-pin surface-mount package of 0.170 inch max. height and 0.679 inch x 0.447 inch length and breadth. Not surprisingly the input and output pins are on the opposite shorter dimensions.
Nominal gain is a typical 20 dB with inputs from -4 dBm to +2 dBm, although the characteristic at 12.5 GHz shows a higher available gain of about 23 dB at -6 dBm input and with gain still available out to +10 dBm input, but falling to about 14 dB. Gain is also available out to 20 GHz (about 10 dB at -4 dBm input.) The 1-dB compression point is at a typical +22 dBm output level.
S11 and S22 are both better than -10 dB across the range with S22 much better (about -18 dB) up to 3 GHz; there is then an obvious correction effect and it climbs to better than -30 dB at about 5 GHz and then falls rapidly to -10 dB at 10 GHz. Input and output capacitor coupling is included within the package but external decoupling is required as well as a small peaking inductor.
The MDA-1220-08S is a two-stage non-inverting GaAs amplifier and, because of the nature of the beast the operating conditions are a little strange: The first stage requires a supply rail of +9 V to +10 V with a bias of typically -0.5 V; the second stage requires 6 V and -4 V. The first stage draws a typical 150 mA, while the second takes a typical 300 mA.
While designed primarily for operation from 9.953 GHz to 12.5 GHz for NRZ or RZ signals, for which it will be widely adopted, the part may also find some other interesting uses, particularly because of its size.
The MDA-1220-08S driver amplifier is sampling and will be in production Q2 2003, priced under $500 in high volume.