What constitutes a pi-network?

A pi-network is a specific type of circuit configuration that resembles the Greek letter "π". It typically consists of two reactive components (capacitors or inductors) and one reactive counterpart connected in between. In this context, when we refer to "two capacitors and one inductor" or "two inductors and one capacitor," we are describing the standard arrangement of a pi-network, which allows for matching impedances in RF circuits or filtering applications.

The arrangement of two capacitors in parallel with an inductor enables the formation of a filter circuit that is versatile for tuning frequencies in RF applications, providing significant impedance transformation. This enables optimal performance in transmitting or receiving signals by reducing losses at desired frequencies while isolating unwanted signals.

The other options do not fit the definition of a pi-network, as they lack the required combination of two reactive components and one other component that creates the distinct configuration necessary for this type of network. Understanding this aspect is crucial for anyone studying circuit theory in the context of communications.