The phrase "are first designed for" is correct and usable in written English.
It can be used when discussing the initial purpose or intended use of a product, service, or system.
Example: "These tools are first designed for beginners, ensuring that they are user-friendly and easy to understand."
Alternatives: "are primarily intended for" or "are initially created for".
The multipliers are first designed for different load capacitances using different structures and different number of stages.
To achieve these goals the structures are first designed for equal performance metrics such as: gain bandwidth product, phase margin and settling time.
For such regard, opamps are first designed for equal performance metrics such as: gain bandwidth product, phase margin and settling time.
Vehicular ad hoc networks (VANETs) [1] are first designed for safety applications; afterwards, a series of applications for increasing traffic efficiency and providing comfort to the vehicle's passengers are proposed.
Specific high-order node-centered finite differences and selective filters removing grid-to-grid oscillations are first designed for the discretization of the buffer region between a Δx-grid domain and 2Δx-grid domain.
The typeface (which was first designed for printed posters) had to stand out with bold clarity from the visual clutter of Edwardian London, a place plastered with competing commercial slogans emblazoned in ever more elaborate scripts.
This system was first designed for the pilot scheme of the current research study.
This technology was first designed for biodiesel production using methanol and ethanol.
The coarse actuator loop is first designed for basic performance and stability, using estimated state feedback.
An optimal robust Kalman-type recursive filter is first designed for each subsystem.
A high gain observer is first designed for the delay-free and continuous output measurement case.
