The traditional design of solution processed single-walled carbon nanotube (SWCNT) thin film transistors (TFTs) often have large active areas. This results in unusual gate leakage currents with high magnitudes that vary with applied voltages. In this paper, we report an improved structure for a solution processed SWCNT based TFT. The unusual gate leakage current in the improved structure is resolved via a simple patterning of the SWCNT active layer to confine it to the channel region. This improved TFT has a gate leakage current that is nearly 12 times lower than the gate leakage current of a traditional TFT design with the same dimensions (aside from the active area) in the on state. The variation in gate leakage current with applied voltages is similarly reduced. To take advantage of solution based fabrication processes, the active layer and electrodes of our TFTs were fabricated with solution based depositions. The improved TFT has an 8.10 cm2 V-1 s-1 mobility and an approximate on/off ratio of 30,100. The performance of the TFT can be further improved in the future by increasing SWCNT solution incubation time and reducing the channel size.