Rockwell joins the high-speed club
A collaboration headed by US-based Rockwell Scientific Company has made a 152 GHz static frequency divider circuit using InP double heterojunction bipolar transistor (DHBT) technology.
Rockwell s work is part of the Defense Advanced Research Project Agency (DARPA) funded program called "technology for frequency agile digitally synthesized transmitters (TFAST)".
Bobby Brar, Rockwell Scientific s program manager for TFAST, told Compoundsemiconductor.net that other program participants, Northrop Grumman Space Technology, HRL Labs, and BAE Systems/Vitesse (see related story) have also achieved results in the 150-153 GHz range.
"Digital circuit performance has increased from 100GHz to 150GHz in 18 months, which is an unbelievable feat," added Brar.
Rockwell s DHBTs have smaller lateral and vertical dimensions than standard devices, allowing them to be operated at higher currents, explained Brar. Higher currents equate to lower charging times for device and load capacitances, leading to the higher operating speed.
The company claims that its DHBTs provide high electrical breakdown, low phase noise, and wide bandwidth for use in systems such as in-flight reprogrammable satellite communications links and millimeter-wave transmitters.
Brar explained that Rockwell intends to produce these devices commercially in the future. The aim of second phase of the TFAST program involves increasing the functionality in either digital or mixed-signal circuits through higher levels of integration.
"The near-term applications of TFAST are focused on the high-performance needs of military systems, but the potential for future commercial uses are great, especially in wireless and telecommunication applications," said Brar.
Other participants in the venture included the University of California at Santa Barbara, UK-based epi-wafer company IQE, and the Mayo Clinic.