A waveguide device (105-a, 105-b, 205, 305-a, 305-b, 405, 505), comprising: a housing comprising a first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) and a second set of opposing sidewalls (140-a, 140-b, 340-a, 340-b), wherein the housing comprises a common port at a first end of the housing; a septum (150-a, 150-b, 250, 350-a, 450) disposed within the housing and extending, at a second end of the housing, from a first sidewall (131-a, 231, 331-a, 431) of the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) to a second sidewall (132-a, 132-b, 232, 332-a, 432) of the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) to form a first divided port and a second divided port at the second end of the housing; and a sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) on the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) and the second set of opposing sidewalls (140-a, 140-b, 340-a, 340-b) at a position along a central axis (121-a, 121-b, 221, 321-a, 321-b, 421) of the housing, wherein the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) has a same shape on each of the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) and the second set of opposing sidewalls (140-a, 140-b, 340-a, 340-b), and wherein: the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) comprises a first edge closer to the first end of the housing and a second edge closer to the second end of the housing, the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) has a width in a direction along the central axis (121-a, 121-b, 221, 321-a, 321-b, 421) of the housing, the width being measured between the first edge and the second edge, and the depth of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) varies from one end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) to the other end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) such that a first depth of the first edge at the one end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) is different from a second depth of the second edge at the other end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455). a housing comprising a first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) and a second set of opposing sidewalls (140-a, 140-b, 340-a, 340-b), wherein the housing comprises a common port at a first end of the housing; a septum (150-a, 150-b, 250, 350-a, 450) disposed within the housing and extending, at a second end of the housing, from a first sidewall (131-a, 231, 331-a, 431) of the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) to a second sidewall (132-a, 132-b, 232, 332-a, 432) of the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) to form a first divided port and a second divided port at the second end of the housing; and a sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) on the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) and the second set of opposing sidewalls (140-a, 140-b, 340-a, 340-b) at a position along a central axis (121-a, 121-b, 221, 321-a, 321-b, 421) of the housing, wherein the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) has a same shape on each of the first set of opposing sidewalls (130-a, 130-b, 330-a, 330-b) and the second set of opposing sidewalls (140-a, 140-b, 340-a, 340-b), and wherein: the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) comprises a first edge closer to the first end of the housing and a second edge closer to the second end of the housing, the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) has a width in a direction along the central axis (121-a, 121-b, 221, 321-a, 321-b, 421) of the housing, the width being measured between the first edge and the second edge, and the depth of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) varies from one end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) to the other end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) such that a first depth of the first edge at the one end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) is different from a second depth of the second edge at the other end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455). the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) comprises a first edge closer to the first end of the housing and a second edge closer to the second end of the housing, the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) has a width in a direction along the central axis (121-a, 121-b, 221, 321-a, 321-b, 421) of the housing, the width being measured between the first edge and the second edge, and the depth of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) varies from one end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) to the other end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) such that a first depth of the first edge at the one end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455) is different from a second depth of the second edge at the other end of the sidewall feature (155-a, 155-b, 255, 355-a, 355-b, 455).