Introduction:
In electronics, a follower stage, also known as a voltage buffer or unity gain amplifier, is a circuit that has a voltage gain of 1. It is commonly used to isolate different parts of a circuit, provide impedance matching, and prevent loading effects. The input impedance of a follower stage is an important parameter that determines how much the circuit loads the previous stage.

Explanation:
The transconductance of a device is a measure of its ability to convert an input voltage to an output current. In the case of a follower stage, the input impedance is determined by the transconductance of the active device used in the circuit, such as a transistor or an operational amplifier.

When the transconductance increases, it means that the active device has a higher ability to convert an input voltage to an output current. However, this does not directly affect the input impedance of the follower stage. The input impedance is primarily determined by the biasing network and the impedance seen by the input terminals of the active device.

Reasoning:
The input impedance of a follower stage is mainly determined by the biasing network and the impedance seen by the input terminals of the active device. It is not affected by the transconductance of the device itself. Therefore, neglecting channel length modulation, the input impedance of a follower stage remains the same when the transconductance increases.

Conclusion:
In conclusion, neglecting channel length modulation, the input impedance of a follower stage remains the same when the transconductance increases. The input impedance is primarily determined by the biasing network and the impedance seen by the input terminals of the active device. It is important to consider these factors when designing and analyzing follower stages in electronic circuits.