Choosing The Right Fixed Coaxial Attenuator

Coaxial attenuators are resistive networks, pi or t networks, connecter to RF / Microwave connecters. These attenuators are generally accustomed regulate sign ranges in navy & industrial rf & microwave techniques. When selecting the best coaxial attenuator to your utility, one ought to think of sure key parameters.

Connector sort: SMA attenuators, BNC attenuators, & sort N attenuators are quite common. One may also purchase pretty pronto attenuators with TNC, 2.92mm, & 2.4mm connecters. There are few producers who supply QMA, 1.85, SMB, F, & Reverse Polarity (N, SMA, TNC) attenuators. In fact coaxial adapters can in the to the worst degree multiplication be used with any attenuator connecter, even so all of us favor to keep away from them except mandatory.

Choosing The Right Fixed Coaxial Attenuator

Connector materials: Each Brass & Stainless Metal are commonplace. One should watch the related torsion values; a brass sma requires 3-5 in-lbs, a chrome steel sma requires 7-10 in-lbs, relying upon the producer. Utilizing a ten in-lb torsion wrench on a brass sma will commonly twist the sma nut proper off the half! SMA, BNC, Kind N, & TNC attenuators can be found in each supplies, with brass acquiring used for much of industrial functions, & stainless lasting over elevated mates/demates. Undertorquing sure attenuators, just like the sma, may cause degraded efficiency at exaggerated frequencies, typically 15 ghz & above.

Energy CW: For small sign functions to 18ghz 2 Watts is au fon the most generally accessible attenuator, although there are few 0.5watt & 1 watt attenuators additionally accessible. Above 18ghz the alternatives are much less, typically simply 0.5Watts at 50ghz. Likewise beneath 18ghz exaggerated powers can be found, with uncooled 500 watt models at 3ghz commonplace. Energy CW is commonly mere at room temperature, even so derates as temperature will increase; a 2 watt unit @ 25C could entirely deal with 0.5Watts @ 125 C

Frequency: As frequency will increase, the resistive chips have to be made with extra precision, & therefore value extra. Generally accessible bands are 0-6ghz, 0-18ghz, 0-26ghx, 0-40ghz, & 0-50ghz, 0-65ghz. As the development is just a resistive community, the decrease frequency vary will in the to the worst degree multiplication be 0. On the higher frequency restrict is the place one can estimate au fon the most ripple in passband response, & the widest deviation from desired attenuator.

Directionality: Small sign attenuators are bidirectional, both port can be utilised because the enter. A lot of the very excessive energy attenuators are unidirectional, they’ve an enter & output, & draw the DUT backwards is often deadly. It is because excessive energy attenuators use cascaded attenuator chips; possibly 2-3 db inside the first chip, 3-5 inside the second, 6-30 inside the third, successfully spreading the warmth to be dissipated aboard the size of the attenuator. Making use of energy to the output ends in nearly all the facility being dissipated in a single chip which then overheats & fails.

DC Dealing with: Being resistive networks, coaxial attenuators aren’t supposed to deal with DC & will change the DC. Typically the attenuator will dissipate an excessive amount of warmth in its resistive parts & fail. One can bypass the attenuator with dc blocks & bias-t’s. Just few bias passing attenuators can be found which incorporate the dc blocks & bias t’s.

Contact Supplies: Nearly all accessible attenuators use BeCu feminine contacts, & Brass male contacts. Just few client functions will substitute brass for the feminine contacts for value discount, even so these ought to be averted for all even so client functions.

Electrical Specs: One can estimate these specs: VSWR, Attenuation worth, Attenuation truth (tolerance), Frequency (higher), Energy Dealing with CW, Energy Dealing with Peak, Working Temperature Vary, Impedance, Connector Materials, and Contact Materials.

Related Articles

Leave a Reply

Your email address will not be published.

Back to top button