The equivalent input noise for some active circuits does not increase when the signal bandwidth increases or when some of their resistors have a larger value. This seemingly
paradoxical behavior is caused by the different transfer functions for the signal and the respective noise sources associated with these resistors.
Vargas, M; Pallás, R; The seemingly paradoxical noise behaviour some active circuits. IEEE Transactions on Instrumentation and Measurement. 1994, vol. 43, núm. 5, p. 764-767