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Constant Impedance Kz RF Technology by IDT


Kz refers to constant impedance technology implemented in a new line of IDT’s RF switches, which is ideal for dynamic switching between multiple devices and enables high-power ‘hot-switching’ capability where it could otherwise not be considered. Plots compare the difference in VSWR performance for conventional RF switching and Kz switching.  Kz technology results in numerous benefits including a simpler software interface compared to what would be needed to optimize timing when using a conventional RF switch.

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Hello, my name is Dan Terlep. I’m a product definer at IDT’s RF group. What I’m going to tell you about are some of the customer benefits of IDT’s technical innovations used RF products.

Kz or constant impedance technology provides a major performance improvements in maintaining the desired impedance of the RF terminals of an RF switch while it is being switched. Standard RFs switches exhibit large impedance changes while transitioning from RF1 to RF2. Plot shown for a standard single pole two throw switch illustrates the voltage standing wave ratio as a function of time. As you can see the VSWR vary significantly it takes a long time to recover. When used in the yellow chain, the RF switch can cause pulling in the voltage controlled oscillator. When used in a transmit path, the impedance change can cause damage to down-stream powered amplifiers, or an ADC in a receiver, similar of what we saw with the glitching behavior of a standard digital step attenuator.

IDT is developing a line of single pole multi-throw RF switches to eliminate these problems. The bottom plat illustrates VSWR for IDT’s single pole two-throw switch. As you can see the VSWR remains nearly constant.

Kz technology results numerous benefits, including allowing a simpler software interface compared of what would be needed to optimize timing when using a conventional RF switch. Kz technology is ideal for dynamic switching between multiple devices, and enables high power hot-switching capability, where could otherwise not be considered.

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