Comments on "Improvement of broadband feedforward amplifier using photonic bandgap"

A number of technical facts were either claimed or implied in the letter by J. Yoon and C. Seo (see ibid., vol.11, no.11, p.450-2, Nov. 2001). Without clarification or supporting data, the claims presented could mislead the reader into drawing inaccurate conclusions regarding the performance increase of feed forward amplifiers due to the so-called photonic bandgap structure.