Micro Lambda Wireless Inc. has just released a new line of microwave oscillators that has set a new standard for phase noise performance. Utilizing new SiGe transistor technology, oscillators are now available with unparalleled phase noise performance at 20 GHz.

New production transistors have been integrated into wide band thin-film oscillator circuit designs to yield 6 to 18, 8 to 18 and 8 to 20 GHz frequency ranges. Previous wide band oscillator designs were limited in their phase noise performance by the availability of good microwave transistors. Silicon bipolar transistors only operated up to 15 GHz with good performance. Above 15 GHz, designs had to utilize FET transistors, which limited their phase noise performance.

Early in the 1990s Micro Lambda Wireless set the standard for 8 to 20 GHz YIG-tuned oscillators with phase noise performance of –108 dBc/Hz at 100 kHz offset. Now the company has set a new standard for phase noise performance at 20 GHz with guaranteed phase noise of –123 dBc/Hz at 100 kHz offset. This is a 15 dB noise improvement over previous designs. Figure 1 shows the new 8 to 20 GHz oscillator’s phase noise performance versus frequency for both 10 and 100 kHz offset frequencies.

The MLXB-Extreme series of oscillators is comprised of the MXLB-0818 (8 to 18 GHz), MLXB-0618 (6 to 18 GHz) and MLXB-0820 (8 to 20 GHz) YIG-tuned oscillators. They operate from +12 and –5 VDC bias voltages and utilize a low power heater operating at +12 VDC as well. High output power levels of +14 to +15 dBm minimum, depending on frequency band, are available in the standard products. Wide bandwidth FM coils of 2 MHz minimum are provided for phase locking and/or modulation throughout the product offering. Figure 2 shows the Extreme series oscillator’s typical frequency error and power output versus frequency.

Standard units are available operating over the 0° to +65°C temperature range. Models are available operating over the extended temperature range of –40° to +85°C on special order.

The oscillators utilize thin-film construction for superior reliability and low cost, and are available in standard 1.25" cube or 1.75" cylinder packages that operate over both commercial and military environments. Units up to 18 GHz are also available in 1" cube packages for commercial applications, making all the units in this new series mechanically interchangeable with existing designs. All units in this new series can be ordered with optional integrated or remote analog, 12-bit TTL or 16-bit serial drivers.

These new oscillators are ideal for test and measurement designs where previous design architectures utilized lower frequency oscillators with the higher frequency ranges obtained by multiplication. Utilizing these new low noise sources could make it possible to change the architecture of new designs to utilize higher frequency sources in the fundamental mode and minimize the multiplication factors to obtain higher frequencies. An added benefit could be the potential of further improving lower frequency phase noise performance by dividing the frequencies of these higher frequency oscillators down, thereby gaining phase noise performance. Additional applications include communications, SatCom and TeleCom, wide band receivers for SIGINT and ELINT, ECM, EW, and a multitude of general-purpose applications.

Micro Lambda Wireless Inc.,
Fremont, CA (510) 770-9221,