CDI Blog For Engineers

Gain Slope Issues in Microwave Modules?

Gain Slope Issues in Microwave Modules?

Physical constraints for broadband operation

If you are a microwave hardware engineer you most likely have had a few sobering experiences when you test your new design the first time, particularly wideband high frequency modules –they almost never look like the model. Many of the bigger issues come down to physics. Broadband modules e.g. 2 to 18 GHz virtually always have gain roll-off at the high end of the band, from a combination of transistor and package parasitic L’s & C’s give rise to gain roll-off and VSWR mismatch losses, while interconnect transmission lines have increasing loss with frequency.

To achieve good EW module signal fidelity over such frequency ranges requires thin dielectric interconnect substrates for:

1) Low ground via inductance for SMT amplifiers and RF components
2) 50 ohm line widths commensurate with SMT component signal pads
3) High isolation at high frequencies.

Further, any components in the RF signal path should have a signal contact width that closely matches the 50 ohm line width to prevent reflections (VSWR) which degrade signal fidelity. Typical construction has transmission line widths in the 0.010 to 0.02 inch line widths to achieve 50 ohm characteristic impedance. A consequence of module measured performance deviating from model prediction is an in ability to pre-plan effectively to compensate for gain slope issues.

Click here to read more…

Click here to download the White Paper for complete information.
About Component Distributors Inc. (CDI)
Component Distributors Inc. (CDI) is a High Tech Franchised Electronics Stocking Distributor providing RF & Microwave and Wireless Communications component distribution worldwide since 1970. CDI’s RF & Microwave products include a large market selection of amplifiers, control components, design kits, discrete semiconductors, integrated modules and chipsets, passives, rf interconnect, and signal generation.
Component Distributors, Inc. (CDI)

Click Here to Submit a Technical Inquiry
Click Here to Download CDI’s RF & Microwave Brochure
Toll-Free: 1-800-777-7334