Source google image: https://www.researchgate.net/profile/Sung_Woo_Lee/publication/224620740/figure/fig7/AS:302870965571587@1449221473176/b-Measured-return-losses-RL-and-isolation-of-twin-feed-horn-for-60-cm-reflector_Q320.jpg
Isolation 60 cm
Source google image: https://www.researchgate.net/profile/Sung_Woo_Lee/publication/224620740/figure/fig7/AS:302870965571587@1449221473176/b-Measured-return-losses-RL-and-isolation-of-twin-feed-horn-for-60-cm-reflector_Q320.jpg