The T-matching structure is indicated with the parameters x and y as shown in Fig. 8. Increasing the value of x and y will increase the resistance as well as the reactance of the antenna as shown in the Fig. 12 and 13 respectively. Therefore, the antenna impedance can be easily matched to the chip impedance only by adjusting the length of x and y, while other parameters remain the same. Increasing the value of x will shift the frequency slightly to the higher frequency, while increasing the value of y will shift the frequency slightly to the lower frequency. Therefore the x and y parameters can be used for small adjustment of resonant frequency as well