Table 4 Extracted parameter with important properties of the unit cell.

From: Inductively tuned modified split ring resonator based quad band epsilon negative (ENG) with near zero index (NZI) metamaterial for multiband antenna performance enhancement

Parameter

Resonance/near zero Frequency(GHz)

Bandwidth(GHz)

Bandwidth threshold

S21

2.38, 4.24, 5.98, 9.55, 12.1, 14.34

0.14, 0.55, 0.46, 1.89, 0.2, 0.3

S21 < − 10 dB

\(\varepsilon_{r}\)

2.381, 4.28, 6.06, 9.68, 12.2, 14.53

0.21, 0.61, 0.64, 1.21, 0.26, 0.53

\(\varepsilon_{r}\) < 0

\(\mu_{r}\)

2.38, 4.28, 6.06, 9.75, 12.15, 14.47

0.25, 0.91, 0.66, 1.75, 0.2, 0.56

\(\mu_{r}\) < 0.3

n

2.381, 4.28, 6.08,9.68, 12.3,14.67

0.2, .07, 0.7, 1.14, 0.3, 2.7

n < 1