In this work, the frequency response of single gate organic thin film transistor (OTFT)‐based common source (CS) voltage amplifier is analyzed. Also, the contact‐channel resistance models are developed to validate the lower/upper cutoff frequency and mid‐band gain. The bandwidth of single gate bottom contact (BC) OTFT‐based amplifier is found to be 16 GHz, but the gain is quite low than the predicted due to its lower transconductance. Surprisingly, voltage gain is improved by four times (12.6 dB more) for dual gate TFT‐based amplifier. Moreover, the bandwidth (1 MHz) is also reasonably good. On applying top gate, biasing the gain is enhanced by 46%. Furthermore, two modified single gate BC structures, ditch and elevated source/drain (S/D) contacts, are incorporated to further augment the amplifier characteristics. Correspondingly, it shows a significant enhancement of 45% and 39% in the gain than that of normal BC. Additionally, the bandwidth is observed to be large and obtained as 100 and 96 MHz, which is also close to the expected analytically.