''' Cable elements, coaxial and triaxial ''' from __future__ import annotations from typing import Optional import math import warnings from ..segments import Segment, SegmentArc from .elements import Element2Term, gap class Coax(Element2Term): ''' Coaxial cable element. Args: length: Total length of the cable, excluding lead extensions. [default: 3] radius: Radius of shield [default: 0.3] leadlen: Distance (x) from start of center conductor to start of shield. [default: 0.6] Anchors: * shieldstart * shieldstart_top * shieldend * shieldend_top * shieldcenter * shieldcenter_top ''' _element_defaults = { 'length': 3, 'leadlen': 0.6, 'radius': 0.3, } def __init__(self, *, length: Optional[float] = None, radius: Optional[float] = None, leadlen: Optional[float] = None, **kwargs): super().__init__(**kwargs) _leadlen = self.params['leadlen'] _length = self.params['length'] _radius = self.params['radius'] self.segments.append(Segment( # Center conductor [(0, 0), (_leadlen, 0), gap, (_length-_leadlen+_radius/2, 0), (_length, 0)])) self.segments.append(Segment( [(_leadlen, _radius), (_length-_leadlen, _radius)])) # Top self.segments.append(Segment( [(_leadlen, -_radius), (_length-_leadlen, -_radius)])) # Bottom self.segments.append(SegmentArc( (_leadlen, 0), width=_radius, height=_radius*2, theta1=0, theta2=360)) self.segments.append(SegmentArc( (_length-_leadlen, 0), width=_radius, height=_radius*2, theta1=270, theta2=90)) self.anchors['shieldstart'] = (_leadlen, -_radius) self.anchors['shieldstart_top'] = (_leadlen, _radius) self.anchors['shieldend'] = (_length-_leadlen, -_radius) self.anchors['shieldend_top'] = (_length-_leadlen, _radius) self.anchors['shieldcenter'] = (_length/2, -_radius) self.anchors['shieldcenter_top'] = (_length/2, _radius) if _radius/2 > _leadlen: warnings.warn('Coax leadlen < radius/2. Coax may be malformed.') if _leadlen*2 > _length: warnings.warn('Coax length < 2*leadlen. Coax may be malformed.') class Triax(Element2Term): ''' Triaxial cable element. Args: length: Total length of the cable [default: 3] radiusinner: Radius of inner guard [default: 0.3] radiusouter: Radius of outer shield [default: 0.6] leadlen: Distance (x) from start of center conductor to start of guard. [default: 0.6] shieldofststart: Distance from start of inner guard to start of outer shield [default: 0.3] shieldofstend: Distance from end of outer shield to end of inner guard [default: 0.3] Anchors: * shieldstart * shieldstart_top * shieldend * shieldend_top * shieldcenter * shieldcenter_top * guardstart * guardstart_top * guardend * guardend_top ''' _element_defaults = { 'length': 3, 'leadlen': 0.6, 'radiusinner': 0.3, 'radiusouter': 0.6, 'shieldofststart': 0.3, 'shieldofstend': 0.3 } def __init__(self, *, length: Optional[float] = None, leadlen: Optional[float] = None, radiusinner: Optional[float] = None, radiusouter: Optional[float] = None, shieldofststart: Optional[float] = None, shieldofstend: Optional[float] = None, **kwargs): super().__init__(**kwargs) r1 = self.params['radiusinner'] r2 = self.params['radiusouter'] _length = self.params['length'] _leadlen = self.params['leadlen'] _shieldofstend = self.params['shieldofstend'] _shieldofststart = self.params['shieldofststart'] if r2 < r1: raise ValueError('Triax inner radius > outer radius') xshield = r2/2 * math.sqrt(1 - r1**2/r2**2) if _shieldofststart - xshield > -r1/2: thetashield = 180 - math.degrees(math.atan2(r1, xshield)) else: thetashield = 180 if _length - _leadlen - _shieldofstend + r2 < _length: # Include the inner guard on output side self.segments.append(Segment( # Center conductor (first) [(0, 0), (_leadlen, 0), gap, (_length-_leadlen+r1/2, 0), (_length, 0)])) self.segments.append(Segment( [(_length-_leadlen-_shieldofstend+xshield, r1), (_length-_leadlen, r1)])) # guard (inner) top/right self.segments.append(Segment( [(_length-_leadlen-_shieldofstend+xshield, -r1), (_length-_leadlen, -r1)])) # guard (inner) bottom/right self.segments.append(SegmentArc( (_length-_leadlen, 0), width=r1, height=r1*2, theta1=270, theta2=90)) else: # Don't include inner guard on output side self.segments.append(Segment( # Center conductor [(0, 0), (_leadlen, 0), gap, (_length-_leadlen-_shieldofstend+r2/2, 0)])) # Start with shapes that are always shown... self.segments.append(Segment( # guard (inner) top/left [(_leadlen, r1), (_leadlen+_shieldofststart+xshield, r1)])) self.segments.append(Segment( # guard (inner) bottom/left [(_leadlen, -r1), (_leadlen+_shieldofststart+xshield, -r1)])) self.segments.append(Segment( # shield (outer) top [(_leadlen+_shieldofststart, r2), (_length-_leadlen-_shieldofstend, r2)])) self.segments.append(Segment( # shield (outer) bottom [(_leadlen+_shieldofststart, -r2), (_length-_leadlen-_shieldofstend, -r2)])) self.segments.append(SegmentArc( (_leadlen, 0), width=r1, height=r1*2, theta1=0, theta2=360)) self.segments.append(SegmentArc( (_leadlen+_shieldofststart, 0), width=r2, height=r2*2, theta1=-thetashield, theta2=thetashield)) self.segments.append(SegmentArc( (_length-_leadlen-_shieldofstend, 0), width=r2, height=r2*2, theta1=270, theta2=90)) self.anchors['guardstart'] = (_leadlen, -r1) self.anchors['guardstart_top'] = (_leadlen, r1) self.anchors['guardend'] = (_length-_leadlen, -r1) self.anchors['guardend_top'] = (_length-_leadlen, r1) self.anchors['shieldstart'] = (_leadlen+_shieldofststart, -r2) self.anchors['shieldstart_top'] = (_leadlen+_shieldofststart, r2) self.anchors['shieldend'] = (_length-_leadlen-_shieldofstend, -r2) self.anchors['shieldend_top'] = (_length-_leadlen-_shieldofstend, r2) self.anchors['shieldcenter'] = (_length/2, -r2) self.anchors['shieldcenter_top'] = (_length/2, r2) if r2 <= r1: warnings.warn('Triax outer radius < inner radius') if _leadlen+_shieldofststart > _length-_leadlen-_shieldofstend: warnings.warn('Triax too short for outer radius')