Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Amplitude control
Reexamination Certificate
1998-11-06
2001-10-09
Wells, Kenneth B. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Amplitude control
C333S08100R
Reexamination Certificate
active
06300814
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a step attenuator. It specifically relates to a step attenuator used within the microwave band.
2. Prior Art
An ideal feature of the step attenuator is that the difference between loss of the entered signal transmission in respective attenuation mode and through-mode (non-attenuation mode) stays constant over all the frequency bands. However, the ideal feature cannot be attained by using the conventional step attenuators. Specifically, the difference between the transmission loss of the entered signal in the respective attenuation mode and through-mode (non-attenuation mode) changes dependent upon the frequency of an entered signal.
As is mentioned above, since the conventional step attenuators have an attenuation setting error, using them for the purpose of providing a broad-band gain control causes low accuracy in gain settings. It is noted that we define the attenuation setting error to mean the error between the attenuation value, which is decided based upon the difference between the transmission losses in the respective through-mode and attenuation mode, and he default attenuation value.
The attenuation setting error may be a main factor in reducing the attenuation accuracy. Therefore, it is important to decrease the error over the broad band.
SUMMARY OF THE INVENTION
The present invention is provided to solve the above-mentioned problems. Thus, the objective of the present invention is to provide a step attenuator, comprising: a first and second resistors connected in series between an input terminal and an output terminal; a first attenuation changeover/setting circuit connected to the first and second resistors in series; and frequency characteristic adjustment circuit and a third resistor, both connected in series to the joint of the first and second resistors and a ground; wherein: the frequency characteristic adjustment circuit comprises: a transmission line connected between the joint of the first and second resistors, and the third resistor; and a second attenuation changeover/setting circuit connected to the third resistor in a parallel manner, with the transmission line being ‘&lgr;/4−&agr;’ (0≦&agr;≦&lgr;/16) in length, where &lgr; denotes the wave-length of a signal entered into the input terminal.
Another objective of the present invention is to provide a step attenuator, comprising: a plurality of step attenuators connected in series between a group of a plurality of input terminals and a group of a plurality of output terminals; with each step attenuator comprising: a first and second resistors connected in series between an input terminal and an output terminal; a first attenuation changeover/setting circuit connected to the first and second resistors in series; and a frequency characteristic adjustment circuit and a third resistor, both connected in series to the joint of the first and second resistors and a ground; wherein: the frequency characteristic adjustment circuit comprises: a transmission line connected between the joint of the first and second resistors, and the third resistor; and a second attenuation changeover/setting circuit connected to the third resistor in a parallel manner, with the transmission line being ‘&lgr;/4−&agr;’ (0≦&agr;≦&lgr;/16) in length, where &lgr; A denotes the wave-length of a signal entered into the input terminal.
REFERENCES:
patent: 5666089 (1999-06-01), Ehlers
patent: 5796286 (1998-08-01), Otaka
patent: 5912599 (1999-06-01), Beall
NEC Corporation
Sughrue Mion Zinn Macpeak & Seas, PLLC
Wells Kenneth B.
LandOfFree
Step attenuator having shunt circuit equipped with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Step attenuator having shunt circuit equipped with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Step attenuator having shunt circuit equipped with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2601934