Microwave Active Filters Based on Coupled Negative Resistance Method

Abstract

Unclasi _ied 2a. SECURITY CLASSIFICATION AUTHORITY 3 DISTRIBUTION/AVAILA81LITY OF REPORT 2b. DECLASSIFICATION /DOWNGRADING SCHEDULE Approved for public release; distribution unlimited. 1. PERFORMING ORGANIZATION REPORT NUMBER(S) S MONITORING ORGANIZATION REPORT NUMBER(S) Microwave Laboratory Report No. 90-P-2 16i. NAME OF PERFORMING ORGANIZATION 6b OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION

Tunable Microstrip Band Pass Filter with Simple Loss Compensation Method

“…The active filter can achieve the insertion gain or near the zero dB insertion loss. Thus, the drawback of the wideband tunable filter can be overcome by using the active filter with a negative resistance characteristic [4][5]. However, the filter needs extra area and additional power consumption.…”

Analysis of an Active Capacitance Circuit and Its Application to VCO

“…However, the ceramic resonator is not compatible with integrated circuits and the lumped element resonator circuit employed in the integrated circuit is known for low Q factor. In order to improve the quality factor, the negative resistance circuit [6]- [7] can be a useful alternative to compensate the loss from a passive resonator. In spite of high-Q, it cannot have been used in commercial products because of its instability, high noise-figure and low power handling capacity.…”

Perfectly-matched bandstop filters using lossy resonators

“…As filter selectivity is limited by the losses associated with the technology used to realize the filter, it is desirable to use design techniques which take the effects of losses into account. Such techniques include passive methods such as predistortion [1], and active approaches [2]. Active approaches suffer from issues such as their inherent nonlinearity which make their use for many applications limited [3].…”